Principles of modulation processing in monaural vs. binaural hearing

DEFF Research Database (Denmark)

Piechowiak, Tobias

2005-01-01

Several phenomena have been investigated that facilitate the perception of masked sound as there are binaural masking level differences (BMLD) and comodulation masking release (CMR). It is assumed that both across-channel CMR and high-frequency BMLD use envelope correlation between different...... channels as a detection cue. Durlach [1] introduced the equalization-cancellation (EC) approach as an across-channel mechanism for explaining BMLD and it was recently used to quantitatively account for many binaural listening experiments. Buus [2] was the first to suggest that an EC-type mechanism could...

Covariation of binaural, concurrently-measured spontaneous otoacoustic emissions.

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Penner, M J; Brauth, S E; Jastreboff, P J

1994-03-01

Simultaneous recordings of binaural spontaneous otoacoustic emissions (SOAEs) were made for 2 female subjects. For SOAEs below about 3.6 kHz measured within a testing session, the frequencies of nearby monaural and binaural SOAEs tended to move in tandem, whereas widely separated SOAEs did not. Across many testing sessions spanning a menstrual cycle, all monaural and binaural SOAE frequencies shifted in tandem. Possible mechanisms consistent with these results are discussed.

Relating the absence of binaural pitch percept to retro-cochlear impairment

DEFF Research Database (Denmark)

Santurette, Sébastien; Dau, Torsten

Binaural pitch stimuli, created by introducing an interaural phase difference over a narrow band of otherwise diotic white noise, produce an immediate tonal sensation with a pitch close to the centre of the phase-shifted band. In Santurette and Dau [Hear. Res. 223(1-2):29-47, 2007], it was shown...... that the salience of binaural pitch was affected by hearing impairment. Specifically, for subjects with a sensorineural impairment, binaural pitch perception was weaker than the normal-hearing average but the pitch sensation was immediately present. In contrast, no binaural pitch sensation at all was found...... for the (only) two subjects with damage at central stages. The aim of the present study is to clarify whether such a sharp distinction between levels of impairment can be made using binaural pitch stimuli. A pitch detection test was performed by three groups of subjects with: 1) normal hearing; 2) a cochlear...

A quantitative electroencephalographic study of meditation and binaural beat entrainment.

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Lavallee, Christina F; Koren, Stanley A; Persinger, Michael A

2011-04-01

The study objective was to determine the quantitative electroencephalographic correlates of meditation, as well as the effects of hindering (15 Hz) and facilitative (7 Hz) binaural beats on the meditative process. The study was a mixed design, with experience of the subject as the primary between-subject measure and power of the six classic frequency bands (δ, θ, low α, high α, β, γ), neocortical lobe (frontal, temporal, parietal, occipital), hemisphere (left, right), and condition (meditation only, meditation with 7-Hz beats, meditation with 15-Hz beats) as the within-subject measures. The study was conducted at Laurentian University in Sudbury, Ontario, Canada. The subjects comprised novice (mean of 8 months experience) and experienced (mean of 18 years experience) meditators recruited from local meditation groups. Experimental manipulation included application of hindering and facilitative binaural beats to the meditative process. Experienced meditators displayed increased left temporal lobe δ power when the facilitative binaural beats were applied, whereas the effect was not observed for the novice subjects in this condition. When the hindering binaural beats were introduced, the novice subjects consistently displayed more γ power than the experienced subjects over the course of their meditation, relative to baseline. Based on the results of this study, novice meditators were not able to maintain certain levels of θ power in the occipital regions when hindering binaural beats were presented, whereas when the facilitative binaural beats were presented, the experienced meditators displayed increased θ power in the left temporal lobe. These results suggest that the experienced meditators have developed techniques over the course of their meditation practice to counter hindering environmental stimuli, whereas the novice meditators have not yet developed those techniques.

The Relationship Between Intensity Coding and Binaural Sensitivity in Adults With Cochlear Implants.

Science.gov (United States)

Todd, Ann E; Goupell, Matthew J; Litovsky, Ruth Y

Many bilateral cochlear implant users show sensitivity to binaural information when stimulation is provided using a pair of synchronized electrodes. However, there is large variability in binaural sensitivity between and within participants across stimulation sites in the cochlea. It was hypothesized that within-participant variability in binaural sensitivity is in part affected by limitations and characteristics of the auditory periphery which may be reflected by monaural hearing performance. The objective of this study was to examine the relationship between monaural and binaural hearing performance within participants with bilateral cochlear implants. Binaural measures included dichotic signal detection and interaural time difference discrimination thresholds. Diotic signal detection thresholds were also measured. Monaural measures included dynamic range and amplitude modulation detection. In addition, loudness growth was compared between ears. Measures were made at three stimulation sites per listener. Greater binaural sensitivity was found with larger dynamic ranges. Poorer interaural time difference discrimination was found with larger difference between comfortable levels of the two ears. In addition, poorer diotic signal detection thresholds were found with larger differences between the dynamic ranges of the two ears. No relationship was found between amplitude modulation detection thresholds or symmetry of loudness growth and the binaural measures. The results suggest that some of the variability in binaural hearing performance within listeners across stimulation sites can be explained by factors nonspecific to binaural processing. The results are consistent with the idea that dynamic range and comfortable levels relate to peripheral neural survival and the width of the excitation pattern which could affect the fidelity with which central binaural nuclei process bilateral inputs.

The impact of binaural beats on creativity

Directory of Open Access Journals (Sweden)

Susan A. Reedijk

2013-11-01

Full Text Available Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale – mood State questionnaire (PANAS-S and affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs. Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBR were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods.

The impact of binaural beats on creativity.

Science.gov (United States)

Reedijk, Susan A; Bolders, Anne; Hommel, Bernhard

2013-01-01

Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale-mood State questionnaire (PANAS-S) and an affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs). Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBRs were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods.

Time-Varying Distortions of Binaural Information by Bilateral Hearing Aids

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Rodriguez, Francisco A.; Portnuff, Cory D. F.; Goupell, Matthew J.; Tollin, Daniel J.

2016-01-01

In patients with bilateral hearing loss, the use of two hearing aids (HAs) offers the potential to restore the benefits of binaural hearing, including sound source localization and segregation. However, existing evidence suggests that bilateral HA users’ access to binaural information, namely interaural time and level differences (ITDs and ILDs), can be compromised by device processing. Our objective was to characterize the nature and magnitude of binaural distortions caused by modern digital behind-the-ear HAs using a variety of stimuli and HA program settings. Of particular interest was a common frequency-lowering algorithm known as nonlinear frequency compression, which has not previously been assessed for its effects on binaural information. A binaural beamforming algorithm was also assessed. Wide dynamic range compression was enabled in all programs. HAs were placed on a binaural manikin, and stimuli were presented from an arc of loudspeakers inside an anechoic chamber. Stimuli were broadband noise bursts, 10-Hz sinusoidally amplitude-modulated noise bursts, or consonant–vowel–consonant speech tokens. Binaural information was analyzed in terms of ITDs, ILDs, and interaural coherence, both for whole stimuli and in a time-varying sense (i.e., within a running temporal window) across four different frequency bands (1, 2, 4, and 6 kHz). Key findings were: (a) Nonlinear frequency compression caused distortions of high-frequency envelope ITDs and significantly reduced interaural coherence. (b) For modulated stimuli, all programs caused time-varying distortion of ILDs. (c) HAs altered the relationship between ITDs and ILDs, introducing large ITD–ILD conflicts in some cases. Potential perceptual consequences of measured distortions are discussed. PMID:27698258

Age-Related Changes in Binaural Interaction at Brainstem Level.

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Van Yper, Lindsey N; Vermeire, Katrien; De Vel, Eddy F J; Beynon, Andy J; Dhooge, Ingeborg J M

2016-01-01

Age-related hearing loss hampers the ability to understand speech in adverse listening conditions. This is attributed to a complex interaction of changes in the peripheral and central auditory system. One aspect that may deteriorate across the lifespan is binaural interaction. The present study investigates binaural interaction at the level of the auditory brainstem. It is hypothesized that brainstem binaural interaction deteriorates with advancing age. Forty-two subjects of various age participated in the study. Auditory brainstem responses (ABRs) were recorded using clicks and 500 Hz tone-bursts. ABRs were elicited by monaural right, monaural left, and binaural stimulation. Binaural interaction was investigated in two ways. First, grand averages of the binaural interaction component were computed for each age group. Second, wave V characteristics of the binaural ABR were compared with those of the summed left and right ABRs. Binaural interaction in the click ABR was demonstrated by shorter latencies and smaller amplitudes in the binaural compared with the summed monaural responses. For 500 Hz tone-burst ABR, no latency differences were found. However, amplitudes were significantly smaller in the binaural than summed monaural condition. An age-effect was found for 500 Hz tone-burst, but not for click ABR. Brainstem binaural interaction seems to decline with age. Interestingly, these changes seem to be stimulus-dependent.

Sensitivity to binaural timing in bilateral cochlear implant users.

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van Hoesel, Richard J M

2007-04-01

Various measures of binaural timing sensitivity were made in three bilateral cochlear implant users, who had demonstrated moderate-to-good interaural time delay (ITD) sensitivity at 100 pulses-per-second (pps). Overall, ITD thresholds increased at higher pulse rates, lower levels, and shorter durations, although intersubject differences were evident. Monaural rate-discrimination thresholds, using the same stimulation parameters, showed more substantial elevation than ITDs with increased rate. ITD sensitivity with 6000 pps stimuli, amplitude-modulated at 100 Hz, was similar to that with unmodulated pulse trains at 100 pps, but at 200 and 300 Hz performance was poorer than with unmodulated signals. Measures of sensitivity to binaural beats with unmodulated pulse-trains showed that all three subjects could use time-varying ITD cues at 100 pps, but not 300 pps, even though static ITD sensitivity was relatively unaffected over that range. The difference between static and dynamic ITD thresholds is discussed in terms of relative contributions from initial and later arriving cues, which was further examined in an experiment using two-pulse stimuli as a function of interpulse separation. In agreement with the binaural-beat data, findings from that experiment showed poor discrimination of ITDs on the second pulse when the interval between pulses was reduced to a few milliseconds.

Binaural dereverberation based on interaural coherence histograms

DEFF Research Database (Denmark)

Westermann, Adam; Buchholz, Jorg M.; Dau, Torsten

2013-01-01

A binaural dereverberation algorithm is presented that utilizes the properties of the interaural coherence (IC) inspired by the concepts introduced in Allen et al. [J. Acoust. Soc. Am. 62, 912-915 (1977)]. The algorithm introduces a non-linear sigmoidal coherence-to-gain mapping that is controlled...... of the proposed algorithm was objectively and subjectively evaluated in terms of its impacts on the amount of reverberation and overall quality. A binaural spectral subtraction method based on Lebart et al. [Acta Acust. Acust. 87, 359-366 (2001)] and a binaural version of the original method of Allen et al. were...

Human cortical responses to slow and fast binaural beats reveal multiple mechanisms of binaural hearing.

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Ross, Bernhard; Miyazaki, Takahiro; Thompson, Jessica; Jamali, Shahab; Fujioka, Takako

2014-10-15

When two tones with slightly different frequencies are presented to both ears, they interact in the central auditory system and induce the sensation of a beating sound. At low difference frequencies, we perceive a single sound, which is moving across the head between the left and right ears. The percept changes to loudness fluctuation, roughness, and pitch with increasing beat rate. To examine the neural representations underlying these different perceptions, we recorded neuromagnetic cortical responses while participants listened to binaural beats at a continuously varying rate between 3 Hz and 60 Hz. Binaural beat responses were analyzed as neuromagnetic oscillations following the trajectory of the stimulus rate. Responses were largest in the 40-Hz gamma range and at low frequencies. Binaural beat responses at 3 Hz showed opposite polarity in the left and right auditory cortices. We suggest that this difference in polarity reflects the opponent neural population code for representing sound location. Binaural beats at any rate induced gamma oscillations. However, the responses were largest at 40-Hz stimulation. We propose that the neuromagnetic gamma oscillations reflect postsynaptic modulation that allows for precise timing of cortical neural firing. Systematic phase differences between bilateral responses suggest that separate sound representations of a sound object exist in the left and right auditory cortices. We conclude that binaural processing at the cortical level occurs with the same temporal acuity as monaural processing whereas the identification of sound location requires further interpretation and is limited by the rate of object representations. Copyright © 2014 the American Physiological Society.

Evaluation of Long-Term Cochlear Implant Use in Subjects With Acquired Unilateral Profound Hearing Loss: Focus on Binaural Auditory Outcomes.

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Mertens, Griet; De Bodt, Marc; Van de Heyning, Paul

Cochlear implantation (CI) in subjects with unilateral profound sensorineural hearing loss was investigated. The authors of the present study demonstrated the binaural auditory outcomes in a 12- and 36-month prospective cohort outcome study. The present study aimed to do a long-term (LT) evaluation of the auditory outcomes in an analogous study group. LT evaluation was derived from 12 single-sided deaf (SSD) CI recipients and from 11 CI recipients with asymmetric hearing loss (AHL). A structured interview was conducted with each subjects. Speech perception in noise and sound localization were assessed in a CIOFF and in a CION condition. Four binaural effects were calculated: summation effect (S0N0), squelch effect (S0NCI), combined head shadow effect (SCIN0), and spatial release from masking (SRM). At the LT evaluation, the contribution of a CI or a bone conduction device on speech perception in noise was investigated in two challenging spatial configurations in the SSD group. All (23/23) subjects wore their CI 7 days a week at LT follow-up evaluation, which ranged from 3 to 10 years after implantation. In the SSD group, a significant combined head shadow effect of 3.17 dB and an SRM benefit of 4.33 dB were found. In the AHL group, on the other hand, the summation effect (2.00 dB), the squelch effect (2.67 dB), the combined head shadow effect (3.67 dB), and SRM benefit (2.00 dB) were significant at LT testing. In both the spatial challenging configurations, the speech in noise results was significantly worse in the condition with the bone conduction device compared with the unaided condition. No negative effect was found for the CION condition. A significant benefit in the CION condition was found for sound localization compared with the CIOFF condition in the SSD group and in the AHL group. All subjects wore their CI 7 days a week at LT follow-up evaluation. The presence of binaural effects has been demonstrated with speech in noise testing, sound localization

Interaction of Object Binding Cues in Binaural Masking Pattern Experiments.

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Verhey, Jesko L; Lübken, Björn; van de Par, Steven

2016-01-01

Object binding cues such as binaural and across-frequency modulation cues are likely to be used by the auditory system to separate sounds from different sources in complex auditory scenes. The present study investigates the interaction of these cues in a binaural masking pattern paradigm where a sinusoidal target is masked by a narrowband noise. It was hypothesised that beating between signal and masker may contribute to signal detection when signal and masker do not spectrally overlap but that this cue could not be used in combination with interaural cues. To test this hypothesis an additional sinusoidal interferer was added to the noise masker with a lower frequency than the noise whereas the target had a higher frequency than the noise. Thresholds increase when the interferer is added. This effect is largest when the spectral interferer-masker and masker-target distances are equal. The result supports the hypothesis that modulation cues contribute to signal detection in the classical masking paradigm and that these are analysed with modulation bandpass filters. A monaural model including an across-frequency modulation process is presented that account for this effect. Interestingly, the interferer also affects dichotic thresholds indicating that modulation cues also play a role in binaural processing.

The technology of binaural listening

CERN Document Server

2013-01-01

This book reports on the application of advanced models of the human binaural hearing system in modern technology, among others, in the following areas:  binaural analysis of aural scenes, binaural de-reverberation, binaural quality assessment of audio channels, loudspeakers and performance spaces, binaural perceptual coding, binaural processing in hearing aids and cochlea implants, binaural systems in robots, binaural/tactile human-machine interfaces, speech-intelligibility prediction in rooms and/or multi-speaker scenarios. An introduction to binaural modeling and an outlook to the future are provided. Further, the book features a MATLAB toolbox to enable readers to construct their own dedicated binaural models on demand.

Relating binaural pitch perception to the individual listener's auditory profile.

Science.gov (United States)

Santurette, Sébastien; Dau, Torsten

2012-04-01

The ability of eight normal-hearing listeners and fourteen listeners with sensorineural hearing loss to detect and identify pitch contours was measured for binaural-pitch stimuli and salience-matched monaurally detectable pitches. In an effort to determine whether impaired binaural pitch perception was linked to a specific deficit, the auditory profiles of the individual listeners were characterized using measures of loudness perception, cognitive ability, binaural processing, temporal fine structure processing, and frequency selectivity, in addition to common audiometric measures. Two of the listeners were found not to perceive binaural pitch at all, despite a clear detection of monaural pitch. While both binaural and monaural pitches were detectable by all other listeners, identification scores were significantly lower for binaural than for monaural pitch. A total absence of binaural pitch sensation coexisted with a loss of a binaural signal-detection advantage in noise, without implying reduced cognitive function. Auditory filter bandwidths did not correlate with the difference in pitch identification scores between binaural and monaural pitches. However, subjects with impaired binaural pitch perception showed deficits in temporal fine structure processing. Whether the observed deficits stemmed from peripheral or central mechanisms could not be resolved here, but the present findings may be useful for hearing loss characterization.

Binaural sensitivity changes between cortical on and off responses

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Dahmen, Johannes C.; King, Andrew J.; Schnupp, Jan W. H.

2011-01-01

Neurons exhibiting on and off responses with different frequency tuning have previously been described in the primary auditory cortex (A1) of anesthetized and awake animals, but it is unknown whether other tuning properties, including sensitivity to binaural localization cues, also differ between on and off responses. We measured the sensitivity of A1 neurons in anesthetized ferrets to 1) interaural level differences (ILDs), using unmodulated broadband noise with varying ILDs and average binaural levels, and 2) interaural time delays (ITDs), using sinusoidally amplitude-modulated broadband noise with varying envelope ITDs. We also assessed fine-structure ITD sensitivity and frequency tuning, using pure-tone stimuli. Neurons most commonly responded to stimulus onset only, but purely off responses and on-off responses were also recorded. Of the units exhibiting significant binaural sensitivity nearly one-quarter showed binaural sensitivity in both on and off responses, but in almost all (∼97%) of these units the binaural tuning of the on responses differed significantly from that seen in the off responses. Moreover, averaged, normalized ILD and ITD tuning curves calculated from all units showing significant sensitivity to binaural cues indicated that on and off responses displayed different sensitivity patterns across the population. A principal component analysis of ITD response functions suggested a continuous cortical distribution of binaural sensitivity, rather than discrete response classes. Rather than reflecting a release from inhibition without any functional significance, we propose that binaural off responses may be important to cortical encoding of sound-source location. PMID:21562191

Binaural auditory beats affect vigilance performance and mood.

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Lane, J D; Kasian, S J; Owens, J E; Marsh, G R

1998-01-01

When two tones of slightly different frequency are presented separately to the left and right ears the listener perceives a single tone that varies in amplitude at a frequency equal to the frequency difference between the two tones, a perceptual phenomenon known as the binaural auditory beat. Anecdotal reports suggest that binaural auditory beats within the electroencephalograph frequency range can entrain EEG activity and may affect states of consciousness, although few scientific studies have been published. This study compared the effects of binaural auditory beats in the EEG beta and EEG theta/delta frequency ranges on mood and on performance of a vigilance task to investigate their effects on subjective and objective measures of arousal. Participants (n = 29) performed a 30-min visual vigilance task on three different days while listening to pink noise containing simple tones or binaural beats either in the beta range (16 and 24 Hz) or the theta/delta range (1.5 and 4 Hz). However, participants were kept blind to the presence of binaural beats to control expectation effects. Presentation of beta-frequency binaural beats yielded more correct target detections and fewer false alarms than presentation of theta/delta frequency binaural beats. In addition, the beta-frequency beats were associated with less negative mood. Results suggest that the presentation of binaural auditory beats can affect psychomotor performance and mood. This technology may have applications for the control of attention and arousal and the enhancement of human performance.

Binaural Hearing Ability With Bilateral Bone Conduction Stimulation in Subjects With Normal Hearing: Implications for Bone Conduction Hearing Aids.

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Zeitooni, Mehrnaz; Mäki-Torkko, Elina; Stenfelt, Stefan

The purpose of this study is to evaluate binaural hearing ability in adults with normal hearing when bone conduction (BC) stimulation is bilaterally applied at the bone conduction hearing aid (BCHA) implant position as well as at the audiometric position on the mastoid. The results with BC stimulation are compared with bilateral air conduction (AC) stimulation through earphones. Binaural hearing ability is investigated with tests of spatial release from masking and binaural intelligibility level difference using sentence material, binaural masking level difference with tonal chirp stimulation, and precedence effect using noise stimulus. In all tests, results with bilateral BC stimulation at the BCHA position illustrate an ability to extract binaural cues similar to BC stimulation at the mastoid position. The binaural benefit is overall greater with AC stimulation than BC stimulation at both positions. The binaural benefit for BC stimulation at the mastoid and BCHA position is approximately half in terms of decibels compared with AC stimulation in the speech based tests (spatial release from masking and binaural intelligibility level difference). For binaural masking level difference, the binaural benefit for the two BC positions with chirp signal phase inversion is approximately twice the benefit with inverted phase of the noise. The precedence effect results with BC stimulation at the mastoid and BCHA position are similar for low frequency noise stimulation but differ with high-frequency noise stimulation. The results confirm that binaural hearing processing with bilateral BC stimulation at the mastoid position is also present at the BCHA implant position. This indicates the ability for binaural hearing in patients with good cochlear function when using bilateral BCHAs.

Ocular vestibular evoked myogenic potential elicited from binaural air-conducted stimulations: clinical feasibility in patients with peripheral vestibular dysfunction.

Science.gov (United States)

Iwasaki, Shinichi; Egami, Naoya; Inoue, Aki; Kinoshita, Makoto; Fujimoto, Chisato; Murofushi, Toshihisa; Yamasoba, Tatsuya

2013-07-01

Ocular vestibular evoked myogenic potentials (oVEMPs) to binaural air-conducted stimulation (ACS) may provide a convenient way of assessing the crossed vestibulo-ocular reflex in patients with vestibular dysfunction as well as in healthy subjects. To investigate the clinical feasibility of using oVEMPs in response to binaural ACS to assess normal subjects and patients with vestibular dysfunction. The study investigated 24 normal subjects (14 men and 10 women, aged from 23 to 60 years) and 14 patients with unilateral peripheral vestibular dysfunction. Each subject underwent oVEMP testing in response to monaural ACS and binaural ACS (500 Hz tone burst, 135 dBSPL). In normal subjects, bilateral oVEMPs were elicited in 75% of subjects in response to monaural ACS and in 91% in response to binaural ACS. Asymmetry ratios (ARs) of the responses to binaural ACS were significantly smaller than those of the responses to monaural ACS (p binaural ACS. Approximately 30% of patients showed reduced ARs to binaural ACS relative to monaural ACS, primarily due to contamination by uncrossed responses elicited in healthy ears.

Combination of binaural and harmonic masking release effects in the detection of a single component in complex tones.

Science.gov (United States)

Klein-Hennig, Martin; Dietz, Mathias; Hohmann, Volker

2018-03-01

Both harmonic and binaural signal properties are relevant for auditory processing. To investigate how these cues combine in the auditory system, detection thresholds for an 800-Hz tone masked by a diotic (i.e., identical between the ears) harmonic complex tone were measured in six normal-hearing subjects. The target tone was presented either diotically or with an interaural phase difference (IPD) of 180° and in either harmonic or "mistuned" relationship to the diotic masker. Three different maskers were used, a resolved and an unresolved complex tone (fundamental frequency: 160 and 40 Hz) with four components below and above the target frequency and a broadband unresolved complex tone with 12 additional components. The target IPD provided release from masking in most masker conditions, whereas mistuning led to a significant release from masking only in the diotic conditions with the resolved and the narrowband unresolved maskers. A significant effect of mistuning was neither found in the diotic condition with the wideband unresolved masker nor in any of the dichotic conditions. An auditory model with a single analysis frequency band and different binaural processing schemes was employed to predict the data of the unresolved masker conditions. Sensitivity to modulation cues was achieved by including an auditory-motivated modulation filter in the processing pathway. The predictions of the diotic data were in line with the experimental results and literature data in the narrowband condition, but not in the broadband condition, suggesting that across-frequency processing is involved in processing modulation information. The experimental and model results in the dichotic conditions show that the binaural processor cannot exploit modulation information in binaurally unmasked conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Application of binaural beat phenomenon with aphasic patients.

Science.gov (United States)

Barr, D F; Mullin, T A; Herbert, P S

1977-04-01

We investigated whether six aphasics and six normal subjects could binaurally fuse two slightly differing frequencies of constant amplitude. The aphasics were subdivided into two groups: (1) two men who had had mild cerebrovascular accidents (CVAs) during the past 15 months; (2) four men who had had severe CVAs during the last 15 months. Two tones of different frequency levels but equal in intensity were presented dichotically to the subjects at 40 dB sensation level. All subjects had normal hearing at 500 Hz (0 to 25 dB). All six normal subjects and the two aphasics who had had mild CVAs could hear the binaural beats. The four aphasics who had had severe CVAs could not hear them. A 2 X 2 design resulting from this study was compared using chi2 test with Yates correction and was found to be significantly different (P less than .05). Two theories are presented to explain these findings: the "depression theory" and the "temporal time-sequencing theory." Therapeutic implications are also discussed relative to cerebral and/or brain stem involvement in the fusion of binaural stimuli.

Binaural Interference and the Effects of Age and Hearing Loss.

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Mussoi, Bruna S S; Bentler, Ruth A

2017-01-01

The existence of binaural interference, defined here as poorer speech recognition with both ears than with the better ear alone, is well documented. Studies have suggested that its prevalence may be higher in the elderly population. However, no study to date has explored binaural interference in groups of younger and older adults in conditions that favor binaural processing (i.e., in spatially separated noise). Also, the effects of hearing loss have not been studied. To examine binaural interference through speech perception tests, in groups of younger adults with normal hearing, older adults with normal hearing for their age, and older adults with hearing loss. A cross-sectional study. Thirty-three participants with symmetric thresholds were recruited from the University of Iowa community. Participants were grouped as follows: younger with normal hearing (18-28 yr, n = 12), older with normal hearing for their age (73-87 yr, n = 9), and older with hearing loss (78-94 yr, n = 12). Prior noise exposure was ruled out. The Connected Speech Test (CST) and Hearing in Noise Test (HINT) were administered to all participants bilaterally, and to each ear separately. Test materials were presented in the sound field with speech at 0° azimuth and the noise at 180°. The Dichotic Digits Test (DDT) was administered to all participants through earphones. Hearing aids were not used during testing. Group results were compared with repeated measures and one-way analysis of variances, as appropriate. Within-subject analyses using pre-established critical differences for each test were also performed. The HINT revealed no effect of condition (individual ear versus bilateral presentation) using group analysis, although within-subject analysis showed that 27% of the participants had binaural interference (18% had binaural advantage). On the CST, there was significant binaural advantage across all groups with group data analysis, as well as for 12% of the participants at each of the two

Binaural Interference: Quo Vadis?

Science.gov (United States)

Jerger, James; Silman, Shlomo; Silverman, Carol; Emmer, Michele

2017-04-01

The reality of the phenomenon of binaural interference with speech recognition has been debated for two decades. Research has taken one of two avenues; group studies or case reports. In group studies, a sample of the elderly population is tested on speech recognition under three conditions; binaural, monaural right and monaural left. The aim is to determine the percent of the sample in which the expected outcome (binaural score-better-than-either-monaural score) is reversed (i.e., one of the monaural scores is better than the binaural score). This outcome has been commonly used to define binaural interference. The object of group studies is to answer the "how many" question, what is the prevalence of binaural interference in the sample. In case reports the binaural interference conclusion suggested by the speech recognition tests is not accepted until it has been corroborated by other independent diagnostic audiological measures. The aim is to attempt to determine the basis for the findings, to answer the "why" question. This article is at once tutorial, editorial and a case report. We argue that it is time to accept the reality of the phenomenon of binaural interference, to eschew group statistical approaches in search of an answer to the "how many" question, and to focus on individual case reports in search of an answer to the "why" question. American Academy of Audiology.

The effect of binaural beats on verbal working memory and cortical connectivity.

Science.gov (United States)

Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A; Leonessa, Alexander

2017-04-01

Synchronization in activated regions of cortical networks affect the brain's frequency response, which has been associated with a wide range of states and abilities, including memory. A non-invasive method for manipulating cortical synchronization is binaural beats. Binaural beats take advantage of the brain's response to two pure tones, delivered independently to each ear, when those tones have a small frequency mismatch. The mismatch between the tones is interpreted as a beat frequency, which may act to synchronize cortical oscillations. Neural synchrony is particularly important for working memory processes, the system controlling online organization and retention of information for successful goal-directed behavior. Therefore, manipulation of synchrony via binaural beats provides a unique window into working memory and associated connectivity of cortical networks. In this study, we examined the effects of different acoustic stimulation conditions during an N-back working memory task, and we measured participant response accuracy and cortical network topology via EEG recordings. Six acoustic stimulation conditions were used: None, Pure Tone, Classical Music, 5 Hz binaural beats, 10 Hz binaural beats, and 15 Hz binaural beats. We determined that listening to 15 Hz binaural beats during an N-Back working memory task increased the individual participant's accuracy, modulated the cortical frequency response, and changed the cortical network connection strengths during the task. Only the 15 Hz binaural beats produced significant change in relative accuracy compared to the None condition. Listening to 15 Hz binaural beats during the N-back task activated salient frequency bands and produced networks characterized by higher information transfer as compared to other auditory stimulation conditions.

Impact of monaural frequency compression on binaural fusion at the brainstem level.

Science.gov (United States)

Klauke, Isabelle; Kohl, Manuel C; Hannemann, Ronny; Kornagel, Ulrich; Strauss, Daniel J; Corona-Strauss, Farah I

2015-08-01

A classical objective measure for binaural fusion at the brainstem level is the so-called β-wave of the binaural interaction component (BIC) in the auditory brainstem response (ABR). However, in some cases it appeared that a reliable detection of this component still remains a challenge. In this study, we investigate the wavelet phase synchronization stability (WPSS) of ABR data for the analysis of binaural fusion and compare it to the BIC. In particular, we examine the impact of monaural nonlinear frequency compression on binaural fusion. As the auditory system is tonotopically organized, an interaural frequency mismatch caused by monaural frequency compression could negatively effect binaural fusion. In this study, only few subjects showed a detectable β-wave and in most cases only for low ITDs. However, we present a novel objective measure for binaural fusion that outperforms the current state-of-the-art technique (BIC): the WPSS analysis showed a significant difference between the phase stability of the sum of the monaurally evoked responses and the phase stability of the binaurally evoked ABR. This difference could be an indicator for binaural fusion in the brainstem. Furthermore, we observed that monaural frequency compression could indeed effect binaural fusion, as the WPSS results for this condition vary strongly from the results obtained without frequency compression.

Directional hearing aid using hybrid adaptive beamformer (HAB) and binaural ITE array

Science.gov (United States)

Shaw, Scott T.; Larow, Andy J.; Gibian, Gary L.; Sherlock, Laguinn P.; Schulein, Robert

2002-05-01

A directional hearing aid algorithm called the Hybrid Adaptive Beamformer (HAB), developed for NIH/NIA, can be applied to many different microphone array configurations. In this project the HAB algorithm was applied to a new array employing in-the-ear microphones at each ear (HAB-ITE), to see if previous HAB performance could be achieved with a more cosmetically acceptable package. With diotic output, the average benefit in threshold SNR was 10.9 dB for three HoH and 11.7 dB for five normal-hearing subjects. These results are slightly better than previous results of equivalent tests with a 3-in. array. With an innovative binaural fitting, a small benefit beyond that provided by diotic adaptive beamforming was observed: 12.5 dB for HoH and 13.3 dB for normal-hearing subjects, a 1.6 dB improvement over the diotic presentation. Subjectively, the binaural fitting preserved binaural hearing abilities, giving the user a sense of space, and providing left-right localization. Thus the goal of creating an adaptive beamformer that simultaneously provides excellent noise reduction and binaural hearing was achieved. Further work remains before the HAB-ITE can be incorporated into a real product, optimizing binaural adaptive beamforming, and integrating the concept with other technologies to produce a viable product prototype. [Work supported by NIH/NIDCD.

The effect of binaural beats on verbal working memory and cortical connectivity

Science.gov (United States)

Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A.; Leonessa, Alexander

2017-04-01

Objective. Synchronization in activated regions of cortical networks affect the brain’s frequency response, which has been associated with a wide range of states and abilities, including memory. A non-invasive method for manipulating cortical synchronization is binaural beats. Binaural beats take advantage of the brain’s response to two pure tones, delivered independently to each ear, when those tones have a small frequency mismatch. The mismatch between the tones is interpreted as a beat frequency, which may act to synchronize cortical oscillations. Neural synchrony is particularly important for working memory processes, the system controlling online organization and retention of information for successful goal-directed behavior. Therefore, manipulation of synchrony via binaural beats provides a unique window into working memory and associated connectivity of cortical networks. Approach. In this study, we examined the effects of different acoustic stimulation conditions during an N-back working memory task, and we measured participant response accuracy and cortical network topology via EEG recordings. Six acoustic stimulation conditions were used: None, Pure Tone, Classical Music, 5 Hz binaural beats, 10 Hz binaural beats, and 15 Hz binaural beats. Main results. We determined that listening to 15 Hz binaural beats during an N-Back working memory task increased the individual participant’s accuracy, modulated the cortical frequency response, and changed the cortical network connection strengths during the task. Only the 15 Hz binaural beats produced significant change in relative accuracy compared to the None condition. Significance. Listening to 15 Hz binaural beats during the N-back task activated salient frequency bands and produced networks characterized by higher information transfer as compared to other auditory stimulation conditions.

Detection and identification of monaural and binaural pitch contours in dyslexic listeners

DEFF Research Database (Denmark)

Santurette, Sébastien; Dau, Torsten; Poelmans, Hanne

2010-01-01

found that a majority of dyslexic subjects were unable to hear binaural pitch, the latter obtained a clear response of dyslexic listeners to Huggins’ pitch (HP) (Cramer and Huggins, 1958). The present study clarified whether impaired binaural pitch perception is found in dyslexia. Results from a pitch...

Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal.

Science.gov (United States)

McConnell, Patrick A; Froeliger, Brett; Garland, Eric L; Ives, Jeffrey C; Sforzo, Gary A

2014-01-01

Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation), few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics [heart rate variability (HRV)] during post-exercise relaxation. Subjects (n = 21; 18-29 years old) participated in a double-blind, placebo-controlled study during which binaural beats and placebo were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design). At the onset of each visit, subjects exercised for 20-min; post-exercise, subjects listened to either binaural beats ('wide-band' theta-frequency binaural beats) or placebo (carrier tones) for 20-min while relaxing alone in a quiet, low-light environment. Dependent variables consisted of high-frequency (HF, reflecting parasympathetic activity), low-frequency (LF, reflecting sympathetic and parasympathetic activity), and LF/HF normalized powers, as well as self-reported relaxation. As compared to the placebo visit, the binaural-beat visit resulted in greater self-reported relaxation, increased parasympathetic activation and increased sympathetic withdrawal. By the end of the 20-min relaxation period there were no observable differences in HRV between binaural-beat and placebo visits, although binaural-beat associated HRV significantly predicted subsequent reported relaxation. Findings suggest that listening to binaural beats may exert an acute influence on both LF and HF components of HRV and may increase subjective feelings of relaxation.

Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal

Directory of Open Access Journals (Sweden)

Patrick eMcConnell

2014-11-01

Full Text Available Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation, few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics (heart-rate variability (HRV during post-exercise relaxation. Subjects (n = 21; 18-29 years old participated in a double-blind, placebo-controlled study during which binaural beats and placebo were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design. At the onset of each visit, subjects exercised for 20-min; post-exercise, subjects listened to either binaural beats (‘wide-band’ theta-frequency binaural beats or placebo (carrier tone for 20-min while relaxing alone in a quiet, low-light environment. Dependent variables consisted of high frequency (HF, reflecting parasympathetic activity, low frequency (LF, reflecting sympathetic and parasympathetic activity and LF/HF normalized powers, as well as self-reported relaxation. As compared to the placebo visit, the binaural beat visit resulted in greater self-reported relaxation, as well as increased parasympathetic activation and sympathetic withdrawal. By the end of the 20-min relaxation period there were no observable differences in HRV between binaural beat and placebo visits, although binaural-beat associated HRV significantly predicted subsequent reported relaxation. Findings suggest that listening to binaural beats may exert an acute influence on both LF and HF components of HRV and may increase subjective feelings of relaxation.

Binaural frequency selectivity in humans.

Science.gov (United States)

Verhey, Jesko L; van de Par, Steven

2018-01-23

Several behavioural studies in humans have shown that listening to sounds with two ears that is binaural hearing, provides the human auditory system with extra information on the sound source that is not available when sounds are only perceived through one ear that is monaurally. Binaural processing involves the analysis of phase and level differences between the two ear signals. As monaural cochlea processing (in each ear) precedes the neural stages responsible for binaural processing properties it is reasonable to assume that properties of the cochlea may also be observed in binaural processing. A main characteristic of cochlea processing is its frequency selectivity. In psychoacoustics, there is an ongoing discussion on the frequency selectivity of the binaural auditory system. While some psychoacoustic experiments seem to indicate poorer frequency selectivity of the binaural system than that of the monaural processing others seem to indicate the same frequency selectivity for monaural and binaural processing. This study provides an overview of these seemingly controversial results and the different explanations that were provided to account for the different results. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Towards a unifying basis of auditory thresholds: binaural summation.

Science.gov (United States)

Heil, Peter

2014-04-01

Absolute auditory threshold decreases with increasing sound duration, a phenomenon explainable by the assumptions that the sound evokes neural events whose probabilities of occurrence are proportional to the sound's amplitude raised to an exponent of about 3 and that a constant number of events are required for threshold (Heil and Neubauer, Proc Natl Acad Sci USA 100:6151-6156, 2003). Based on this probabilistic model and on the assumption of perfect binaural summation, an equation is derived here that provides an explicit expression of the binaural threshold as a function of the two monaural thresholds, irrespective of whether they are equal or unequal, and of the exponent in the model. For exponents >0, the predicted binaural advantage is largest when the two monaural thresholds are equal and decreases towards zero as the monaural threshold difference increases. This equation is tested and the exponent derived by comparing binaural thresholds with those predicted on the basis of the two monaural thresholds for different values of the exponent. The thresholds, measured in a large sample of human subjects with equal and unequal monaural thresholds and for stimuli with different temporal envelopes, are compatible only with an exponent close to 3. An exponent of 3 predicts a binaural advantage of 2 dB when the two ears are equally sensitive. Thus, listening with two (equally sensitive) ears rather than one has the same effect on absolute threshold as doubling duration. The data suggest that perfect binaural summation occurs at threshold and that peripheral neural signals are governed by an exponent close to 3. They might also shed new light on mechanisms underlying binaural summation of loudness.

Binaural model-based dynamic-range compression.

Science.gov (United States)

Ernst, Stephan M A; Kortlang, Steffen; Grimm, Giso; Bisitz, Thomas; Kollmeier, Birger; Ewert, Stephan D

2018-01-26

Binaural cues such as interaural level differences (ILDs) are used to organise auditory perception and to segregate sound sources in complex acoustical environments. In bilaterally fitted hearing aids, dynamic-range compression operating independently at each ear potentially alters these ILDs, thus distorting binaural perception and sound source segregation. A binaurally-linked model-based fast-acting dynamic compression algorithm designed to approximate the normal-hearing basilar membrane (BM) input-output function in hearing-impaired listeners is suggested. A multi-center evaluation in comparison with an alternative binaural and two bilateral fittings was performed to assess the effect of binaural synchronisation on (a) speech intelligibility and (b) perceived quality in realistic conditions. 30 and 12 hearing impaired (HI) listeners were aided individually with the algorithms for both experimental parts, respectively. A small preference towards the proposed model-based algorithm in the direct quality comparison was found. However, no benefit of binaural-synchronisation regarding speech intelligibility was found, suggesting a dominant role of the better ear in all experimental conditions. The suggested binaural synchronisation of compression algorithms showed a limited effect on the tested outcome measures, however, linking could be situationally beneficial to preserve a natural binaural perception of the acoustical environment.

Binaural Interaction Effects of 30-50 Hz Auditory Steady State Responses.

Science.gov (United States)

Gransier, Robin; van Wieringen, Astrid; Wouters, Jan

Auditory stimuli modulated by modulation frequencies within the 30 to 50 Hz region evoke auditory steady state responses (ASSRs) with high signal to noise ratios in adults, and can be used to determine the frequency-specific hearing thresholds of adults who are unable to give behavioral feedback reliably. To measure ASSRs as efficiently as possible a multiple stimulus paradigm can be used, stimulating both ears simultaneously. The response strength of 30 to 50Hz ASSRs is, however, affected when both ears are stimulated simultaneously. The aim of the present study is to gain insight in the measurement efficiency of 30 to 50 Hz ASSRs evoked with a 2-ear stimulation paradigm, by systematically investigating the binaural interaction effects of 30 to 50 Hz ASSRs in normal-hearing adults. ASSRs were obtained with a 64-channel EEG system in 23 normal-hearing adults. All participants participated in one diotic, multiple dichotic, and multiple monaural conditions. Stimuli consisted of a modulated one-octave noise band, centered at 1 kHz, and presented at 70 dB SPL. The diotic condition contained 40 Hz modulated stimuli presented to both ears. In the dichotic conditions, the modulation frequency of the left ear stimulus was kept constant at 40 Hz, while the stimulus at the right ear was either the unmodulated or modulated carrier. In case of the modulated carrier, the modulation frequency varied between 30 and 50 Hz in steps of 2 Hz across conditions. The monaural conditions consisted of all stimuli included in the diotic and dichotic conditions. Modulation frequencies ≥36 Hz resulted in prominent ASSRs in all participants for the monaural conditions. A significant enhancement effect was observed (average: ~3 dB) in the diotic condition, whereas a significant reduction effect was observed in the dichotic conditions. There was no distinct effect of the temporal characteristics of the stimuli on the amount of reduction. The attenuation was in 33% of the cases >3 dB for

Psychoacoustic evaluation of multichannel reproduced sounds using binaural synthesis and spherical beamforming.

Science.gov (United States)

Song, Wookeun; Ellermeier, Wolfgang; Hald, Jørgen

2011-10-01

The binaural auralization of a 3D sound field using spherical-harmonics beamforming (SHB) techniques was investigated and compared with the traditional method using a head-and-torso simulator (HATS). The new procedure was verified by comparing simulated room impulse responses with measured ones binaurally. The objective comparisons show that there is good agreement in the frequency range between 0.1 and 6.4 kHz. A listening experiment was performed to validate the SHB method subjectively and to compare it to the HATS method. Two musical excerpts, pop and classical, were used. Subjective responses were collected in two head rotation conditions (fixed and rotating) and six spatial reproduction modes, including phantom mono, stereo, and surround sound. The results show that subjective scales of width, spaciousness, and preference based on the SHB method were similar to those obtained for the HATS method, although the width and spaciousness of the stimuli processed by the SHB method were judged slightly higher than the ones using the HATS method in general. Thus, binaural synthesis using SHB may be a useful tool to reproduce a 3D sound field binaurally, while saving considerably on measurement time because head rotation can be simulated based on a single recording. © 2011 Acoustical Society of America

Binaural Pitch Fusion in Bilateral Cochlear Implant Users.

Science.gov (United States)

Reiss, Lina A J; Fowler, Jennifer R; Hartling, Curtis L; Oh, Yonghee

Binaural pitch fusion is the fusion of stimuli that evoke different pitches between the ears into a single auditory image. Individuals who use hearing aids or bimodal cochlear implants (CIs) experience abnormally broad binaural pitch fusion, such that sounds differing in pitch by as much as 3-4 octaves are fused across ears, leading to spectral averaging and speech perception interference. The goal of this study was to determine if adult bilateral CI users also experience broad binaural pitch fusion. Stimuli were pulse trains delivered to individual electrodes. Fusion ranges were measured using simultaneous, dichotic presentation of reference and comparison stimuli in opposite ears, and varying the comparison stimulus to find the range that fused with the reference stimulus. Bilateral CI listeners had binaural pitch fusion ranges varying from 0 to 12 mm (average 6.1 ± 3.9 mm), where 12 mm indicates fusion over all electrodes in the array. No significant correlations of fusion range were observed with any subject factors related to age, hearing loss history, or hearing device history, or with any electrode factors including interaural electrode pitch mismatch, pitch match bandwidth, or within-ear electrode discrimination abilities. Bilateral CI listeners have abnormally broad fusion, similar to hearing aid and bimodal CI listeners. This broad fusion may explain the variability of binaural benefits for speech perception in quiet and in noise in bilateral CI users.

Binaural beat technology in humans: a pilot study to assess neuropsychologic, physiologic, and electroencephalographic effects.

Science.gov (United States)

Wahbeh, Helané; Calabrese, Carlo; Zwickey, Heather; Zajdel, Dan

2007-03-01

When two auditory stimuli of different frequency are presented to each ear, binaural beats are perceived by the listener. The binaural beat frequency is equal to the difference between the frequencies applied to each ear. Our primary objective was to assess whether steady-state entrainment of electroencephalographic activity to the binaural beat occurs when exposed to a specific binaural beat frequency as has been hypothesized. Our secondary objective was to gather preliminary data on neuropsychologic and physiologic effects of binaural beat technology. A randomized, blinded, placebo-controlled crossover experiment in 4 healthy adult subjects. Subjects were randomized to experimental auditory stimulus of 30 minutes of binaural beat at 7 Hz (carrier frequencies: 133 Hz L; 140 Hz R) with an overlay of pink noise resembling the sound of rain on one session and control stimuli of the same overlay without the binaural beat carrier frequencies on the other session. Data were collected during two separate sessions 1 week apart. Neuropsychologic and blood pressure data were collected before and after the intervention; electroencephalographic data were collected before, during, and after listening to either binaural beats or control. Neuropsychologic measures included State Trait Anxiety Inventory, Profile of Mood States, Rey Auditory Verbal List Test, Stroop Test, and Controlled Oral Word Association Test. Spectral and coherence analysis was performed on the electroencephalogram (EEG), and all measures were analyzed for changes between sessions with and without binaural beat stimuli. There were no significant differences between the experimental and control conditions in any of the EEG measures. There was an increase of the Profile of Mood States depression subscale in the experimental condition relative to the control condition (p = 0.02). There was also a significant decrease in immediate verbal memory recall (p = 0.03) in the experimental condition compared to control

Auditory evoked responses to binaural beat illusion: stimulus generation and the derivation of the Binaural Interaction Component (BIC).

Science.gov (United States)

Ozdamar, Ozcan; Bohorquez, Jorge; Mihajloski, Todor; Yavuz, Erdem; Lachowska, Magdalena

2011-01-01

Electrophysiological indices of auditory binaural beats illusions are studied using late latency evoked responses. Binaural beats are generated by continuous monaural FM tones with slightly different ascending and descending frequencies lasting about 25 ms presented at 1 sec intervals. Frequency changes are carefully adjusted to avoid any creation of abrupt waveform changes. Binaural Interaction Component (BIC) analysis is used to separate the neural responses due to binaural involvement. The results show that the transient auditory evoked responses can be obtained from the auditory illusion of binaural beats.

A comparison of auditory evoked potentials to acoustic beats and to binaural beats

OpenAIRE

Pratt, H; Starr, A; Michalewski, HJ; Dimitrijevic, A; Bleich, N; Mittelman, N

2010-01-01

The purpose of this study was to compare cortical brain responses evoked by amplitude modulated acoustic beats of 3 and 6 Hz in tones of 250 and 1000 Hz with those evoked by their binaural beats counterparts in unmodulated tones to indicate whether the cortical processes involved differ. Event-related potentials (ERPs) were recorded to 3- and 6-Hz acoustic and binaural beats in 2000 ms duration 250 and 1000 Hz tones presented with approximately 1 s intervals. Latency, amplitude and source cur...

A comparison of sound quality judgments for monaural and binaural hearing aid processed stimuli.

Science.gov (United States)

Balfour, P B; Hawkins, D B

1992-10-01

Fifteen adults with bilaterally symmetrical mild and/or moderate sensorineural hearing loss completed a paired-comparison task designed to elicit sound quality preference judgments for monaural/binaural hearing aid processed signals. Three stimuli (speech-in-quiet, speech-in-noise, and music) were recorded separately in three listening environments (audiometric test booth, living room, and a music/lecture hall) through hearing aids placed on a Knowles Electronics Manikin for Acoustics Research. Judgments were made on eight separate sound quality dimensions (brightness, clarity, fullness, loudness, nearness, overall impression, smoothness, and spaciousness) for each of the three stimuli in three listening environments. Results revealed a distinct binaural preference for all eight sound quality dimensions independent of listening environment. Binaural preferences were strongest for overall impression, fullness, and spaciousness. Stimulus type effect was significant only for fullness and spaciousness, where binaural preferences were strongest for speech-in-quiet. After binaural preference data were obtained, subjects ranked each sound quality dimension with respect to its importance for binaural listening relative to monaural. Clarity was ranked highest in importance and brightness was ranked least important. The key to demonstration of improved binaural hearing aid sound quality may be the use of a paired-comparison format.

Relaxed Binaural LCMV Beamforming

NARCIS (Netherlands)

Koutrouvelis, A.; Hendriks, R.C.; Heusdens, R.; Jensen, Jesper Rindom

2017-01-01

In this paper, we propose a new binaural beamforming technique, which can be seen as a relaxation of the linearly constrained minimum variance (LCMV) framework. The proposed method can achieve simultaneous noise reduction and exact binaural cue preservation of the target source, similar to the

Binaural Speech Understanding With Bilateral Cochlear Implants in Reverberation.

Science.gov (United States)

Kokkinakis, Kostas

2018-03-08

The purpose of this study was to investigate whether bilateral cochlear implant (CI) listeners who are fitted with clinical processors are able to benefit from binaural advantages under reverberant conditions. Another aim of this contribution was to determine whether the magnitude of each binaural advantage observed inside a highly reverberant environment differs significantly from the magnitude measured in a near-anechoic environment. Ten adults with postlingual deafness who are bilateral CI users fitted with either Nucleus 5 or Nucleus 6 clinical sound processors (Cochlear Corporation) participated in this study. Speech reception thresholds were measured in sound field and 2 different reverberation conditions (0.06 and 0.6 s) as a function of the listening condition (left, right, both) and the noise spatial location (left, front, right). The presence of the binaural effects of head-shadow, squelch, summation, and spatial release from masking in the 2 different reverberation conditions tested was determined using nonparametric statistical analysis. In the bilateral population tested, when the ambient reverberation time was equal to 0.6 s, results indicated strong positive effects of head-shadow and a weaker spatial release from masking advantage, whereas binaural squelch and summation contributed no statistically significant benefit to bilateral performance under this acoustic condition. These findings are consistent with those of previous studies, which have demonstrated that head-shadow yields the most pronounced advantage in noise. The finding that spatial release from masking produced little to almost no benefit in bilateral listeners is consistent with the hypothesis that additive reverberation degrades spatial cues and negatively affects binaural performance. The magnitude of 4 different binaural advantages was measured on the same group of bilateral CI subjects fitted with clinical processors in 2 different reverberation conditions. The results of this work

Binaural room simulation

Science.gov (United States)

Lehnert, H.; Blauert, Jens; Pompetzki, W.

1991-01-01

In every-day listening the auditory event perceived by a listener is determined not only by the sound signal that a sound emits but also by a variety of environmental parameters. These parameters are the position, orientation and directional characteristics of the sound source, the listener's position and orientation, the geometrical and acoustical properties of surfaces which affect the sound field and the sound propagation properties of the surrounding fluid. A complete set of these parameters can be called an Acoustic Environment. If the auditory event perceived by a listener is manipulated in such a way that the listener is shifted acoustically into a different acoustic environment without moving himself physically, a Virtual Acoustic Environment has been created. Here, we deal with a special technique to set up nearly arbitrary Virtual Acoustic Environments, the Binaural Room Simulation. The purpose of the Binaural Room Simulation is to compute the binaural impulse response related to a virtual acoustic environment taking into account all parameters mentioned above. One possible way to describe a Virtual Acoustic Environment is the concept of the virtual sound sources. Each of the virtual sources emits a certain signal which is correlated but not necessarily identical with the signal emitted by the direct sound source. If source and receiver are non moving, the acoustic environment becomes a linear time-invariant system. Then, the Binaural Impulse Response from the source to a listener' s eardrums contains all relevant auditory information related to the Virtual Acoustic Environment. Listening into the simulated environment can easily be achieved by convolving the Binaural Impulse Response with dry signals and representing the results via headphones.

The impact of binaural beats on creativity

OpenAIRE

Susan A. Reedijk; Susan A. Reedijk; Anne eBolders; Anne eBolders; Bernhard eHommel; Bernhard eHommel

2013-01-01

Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through st...

Statistics of natural binaural sounds.

Directory of Open Access Journals (Sweden)

Wiktor Młynarski

Full Text Available Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD and level (ILD disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA. Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

Statistics of natural binaural sounds.

Science.gov (United States)

Młynarski, Wiktor; Jost, Jürgen

2014-01-01

Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD) and level (ILD) disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA). Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

Suitability of the Binaural Interaction Component for Interaural Electrode Pairing of Bilateral Cochlear Implants.

Science.gov (United States)

Hu, Hongmei; Kollmeier, Birger; Dietz, Mathias

2016-01-01

Although bilateral cochlear implants (BiCIs) have succeeded in improving the spatial hearing performance of bilateral CI users, the overall performance is still not comparable with normal hearing listeners. Limited success can be partially caused by an interaural mismatch of the place-of-stimulation in each cochlea. Pairing matched interaural CI electrodes and stimulating them with the same frequency band is expected to facilitate binaural functions such as binaural fusion, localization, or spatial release from masking. It has been shown in animal experiments that the magnitude of the binaural interaction component (BIC) derived from the wave-eV decreases for increasing interaural place of stimulation mismatch. This motivated the investigation of the suitability of an electroencephalography-based objective electrode-frequency fitting procedure based on the BIC for BiCI users. A 61 channel monaural and binaural electrically evoked auditory brainstem response (eABR) recording was performed in 7 MED-EL BiCI subjects so far. These BiCI subjects were directly stimulated at 60% dynamic range with 19.9 pulses per second via a research platform provided by the University of Innsbruck (RIB II). The BIC was derived for several interaural electrode pairs by subtracting the response from binaural stimulation from their summed monaural responses. The BIC based pairing results are compared with two psychoacoustic pairing methods: interaural pulse time difference sensitivity and interaural pitch matching. The results for all three methods analyzed as a function of probe electrode allow for determining a matched pair in more than half of the subjects, with a typical accuracy of ± 1 electrode. This includes evidence for statistically significant tuning of the BIC as a function of probe electrode in human subjects. However, results across the three conditions were sometimes not consistent. These discrepancies will be discussed in the light of pitch plasticity versus less plastic

A comparison of auditory evoked potentials to acoustic beats and to binaural beats.

Science.gov (United States)

Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

2010-04-01

The purpose of this study was to compare cortical brain responses evoked by amplitude modulated acoustic beats of 3 and 6 Hz in tones of 250 and 1000 Hz with those evoked by their binaural beats counterparts in unmodulated tones to indicate whether the cortical processes involved differ. Event-related potentials (ERPs) were recorded to 3- and 6-Hz acoustic and binaural beats in 2000 ms duration 250 and 1000 Hz tones presented with approximately 1 s intervals. Latency, amplitude and source current density estimates of ERP components to beats-evoked oscillations were determined and compared across beat types, beat frequencies and base (carrier) frequencies. All stimuli evoked tone-onset components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude in response to acoustic than to binaural beats, to 250 than to 1000 Hz base frequency and to 3 Hz than to 6 Hz beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left temporal lobe areas. Differences between estimated sources of potentials to acoustic and binaural beats were not significant. The perceptions of binaural beats involve cortical activity that is not different than acoustic beats in distribution and in the effects of beat- and base frequency, indicating similar cortical processing. Copyright 2010 Elsevier B.V. All rights reserved.

Binaural enhancement for bilateral cochlear implant users.

Science.gov (United States)

Brown, Christopher A

2014-01-01

Bilateral cochlear implant (BCI) users receive limited binaural cues and, thus, show little improvement to speech intelligibility from spatial cues. The feasibility of a method for enhancing the binaural cues available to BCI users is investigated. This involved extending interaural differences of levels, which typically are restricted to high frequencies, into the low-frequency region. Speech intelligibility was measured in BCI users listening over headphones and with direct stimulation, with a target talker presented to one side of the head in the presence of a masker talker on the other side. Spatial separation was achieved by applying either naturally occurring binaural cues or enhanced cues. In this listening configuration, BCI patients showed greater speech intelligibility with the enhanced binaural cues than with naturally occurring binaural cues. In some situations, it is possible for BCI users to achieve greater speech intelligibility when binaural cues are enhanced by applying interaural differences of levels in the low-frequency region.

Interaural Level Difference Dependent Gain Control and Synaptic Scaling Underlying Binaural Computation

Science.gov (United States)

Xiong, Xiaorui R.; Liang, Feixue; Li, Haifu; Mesik, Lukas; Zhang, Ke K.; Polley, Daniel B.; Tao, Huizhong W.; Xiao, Zhongju; Zhang, Li I.

2013-01-01

Binaural integration in the central nucleus of inferior colliculus (ICC) plays a critical role in sound localization. However, its arithmetic nature and underlying synaptic mechanisms remain unclear. Here, we showed in mouse ICC neurons that the contralateral dominance is created by a “push-pull”-like mechanism, with contralaterally dominant excitation and more bilaterally balanced inhibition. Importantly, binaural spiking response is generated apparently from an ipsilaterally-mediated scaling of contralateral response, leaving frequency tuning unchanged. This scaling effect is attributed to a divisive attenuation of contralaterally-evoked synaptic excitation onto ICC neurons with their inhibition largely unaffected. Thus, a gain control mediates the linear transformation from monaural to binaural spike responses. The gain value is modulated by interaural level difference (ILD) primarily through scaling excitation to different levels. The ILD-dependent synaptic scaling and gain adjustment allow ICC neurons to dynamically encode interaural sound localization cues while maintaining an invariant representation of other independent sound attributes. PMID:23972599

Instructional Multiple Binaural Stethoscope

Directory of Open Access Journals (Sweden)

Catalina C. Platon

2015-12-01

Full Text Available The stethoscope is an acoustic medical device for auscultation where human ear plays significant part. Long before doctors practiced immediate auscultation meaning placing ear directly on patient’s body by Salinsky (1990, then monaural introduced by Laennec; later binaural, Comins’s invention and Cammann developed further. Several decades numerous innovations made predominantly over chestpiece some had drawbacks. Dr Littman introduced teaching stethoscope with two headset and researcher utilized as prior art.Experimental research method used and the study aimed to determine accuracy and measurement of speed of the device in terms of systolic and diastolic blood pressure and acceptability of user. The subjects were 19 clients and 27 nursing students, government /private registered nurses. The device are comparable to single binaural stethoscope in accuracy performance; speed of sound, former is slightly higher than the latter but still considered as normal; the device are acceptable to users; the utility model have no significant difference in accuracy performance and speed measurements of systolic and diastolic. The utility model may be tried in any acoustic activities and may be pilot tested to the Universities animal science courses, veterinary medicine other Colleges of Nursing and all health allied courses.

The Relationship between Binaural Benefit and Difference in Unilateral Speech Recognition Performance for Bilateral Cochlear Implant Users

Science.gov (United States)

Yoon, Yang-soo; Li, Yongxin; Kang, Hou-Yong; Fu, Qian-Jie

2011-01-01

Objective The full benefit of bilateral cochlear implants may depend on the unilateral performance with each device, the speech materials, processing ability of the user, and/or the listening environment. In this study, bilateral and unilateral speech performances were evaluated in terms of recognition of phonemes and sentences presented in quiet or in noise. Design Speech recognition was measured for unilateral left, unilateral right, and bilateral listening conditions; speech and noise were presented at 0° azimuth. The “binaural benefit” was defined as the difference between bilateral performance and unilateral performance with the better ear. Study Sample 9 adults with bilateral cochlear implants participated. Results On average, results showed a greater binaural benefit in noise than in quiet for all speech tests. More importantly, the binaural benefit was greater when unilateral performance was similar across ears. As the difference in unilateral performance between ears increased, the binaural advantage decreased; this functional relationship was observed across the different speech materials and noise levels even though there was substantial intra- and inter-subject variability. Conclusions The results indicate that subjects who show symmetry in speech recognition performance between implanted ears in general show a large binaural benefit. PMID:21696329

A new binaural detection model based on contralateral inhibition

NARCIS (Netherlands)

Breebaart, D.J.; Kohlrausch, A.G.; Dau, T.; Hohmann, V.; Kollmeier, B.

1999-01-01

Binaural models attempt to explain binaural phenomena in terms of neural mechanisms that extract binaural information from accoustic stimuli. In this paper, a model setup is presented that can be used to simulate binaural detection tasks. In contrast to the most often used cross correlation between

The brain responses to different frequencies of binaural beat sounds on QEEG at cortical level.

Science.gov (United States)

Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

2015-01-01

Beat phenomenon is occurred when two slightly different frequency waves interfere each other. The beat can also occur in the brain by providing two slightly different frequency waves separately each ear. This is called binaural beat. The brain responses to binaural beat are in discussion process whether the brain side and the brain area. Therefore, this study aims to figure out the brain responses to binaural beat by providing different binaural beat frequencies on 250 carrier tone continuously for 30 minutes to participants and using quantitative electroencephalography (QEEG) to interpret the data. The result shows that different responses appear in different beat frequency. Left hemisphere dominance occur in 3 Hz beat within 15 minutes and 15 Hz beat within 5 minutes. Right hemisphere dominance occurs in 10 Hz beat within 25 minute. 6 Hz beat enhances all area of the brain within 10 minutes. 8 Hz and 25 Hz beats have no clearly responses while 40 Hz beat enhances the responses in frontal lobe. These brain responses can be used for brain modulation application to induce the brain activity in further studies.

Binaural auditory outcomes in patients with postlingual profound unilateral hearing loss: 3 years after cochlear implantation.

Science.gov (United States)

Mertens, Griet; Kleine Punte, Andrea; De Bodt, Marc; Van de Heyning, Paul

2015-01-01

The value of cochlear implants (CI) in patients with profound unilateral hearing loss (UHL) and tinnitus has recently been investigated. The authors previously demonstrated the feasibility of CI in a 12- month outcome study in a prospective UHL cohort. The aim of this study was to investigate the binaural auditory outcomes in this cohort 36 months after CI surgery. The 36-month outcome was evaluated in 22 CI users with postlingual UHL and severe tinnitus. Twelve subjects had contralateral normal hearing (single-sided deafness - SSD group) and 10 subjects had a contralateral, mild to moderate hearing loss and used a hearing aid (asymmetric hearing loss - AHL group). Speech perception in noise was assessed in two listening conditions: the CIoff and the CIon condition. The binaural summation effect (S0N0), binaural squelch effect (S0NCI) and the combined head shadow effect (SCIN0) were investigated. Subjective benefit in daily life was assessed by means of the Speech, Spatial and Qualities of Hearing Scale (SSQ). At 36 months, a significant binaural summation effect was observed for the study cohort (2.00, SD 3.82 dB; p binaural effect was not significant 12 months after CI surgery. A binaural squelch effect was significant for the AHL subgroup at 12 months (2.00, SD 4.38 dB; p < 0.05). A significant combined head shadow and squelch effect was also noted in the spatial configuration SCIN0 for the study cohort (4.00, SD 5.89 dB; p < 0.01) and for the AHL subgroup (5.67, SD 6.66 dB; p < 0.05). The SSQ data show that the perceived benefit in daily life after CI surgery remains stable up to 36 months at CIon. CI can significantly improve speech perception in noise in patients with UHL. The positive effects of CIon speech perception in noise increase over time up to 36 months after CI surgery. Improved subjective benefit in daily life was also shown to be sustained in these patients. © 2015 S. Karger AG, Basel.

Binaural loudness summation for directional sounds

DEFF Research Database (Denmark)

Sivonen, Ville Pekka; Ellermeier, Wolfgang

2006-01-01

the binaural loudness summation of the at-ear signals. Even though the effects of HRTFs were taken into account, considerable individual differences in the binaural summation of loudness remained. In order to create conditions in which the directional at-ear changes were identical for all participants......, the present experiment employed 'generic' HRTFs to create directional sounds via binaural synthesis. When inspecting the results of the listening tests, however, large individual differences were still evident, as in the earlier study. The generality of this finding was further corroborated by running...... an independent, inexperienced sample of ten participants exclusively being exposed to the present generic HRTFs. Despite the individual differences, the average results suggest a relatively simple rule for combining the binaural input when carrying out acoustical measurements using an artificial head...

A binaural advantage in the subjective modulation transfer function with simple impulse responses

DEFF Research Database (Denmark)

Thompson, Eric Robert; Dau, Torsten

2008-01-01

into account that humans listen with two ears. There can be large interaural phase differences in the modulation transfer functions, which can create detectable interaural level difference fluctuations. Measurements were made to determine whether these interaural modulation phase differences can be used......The speech transmission index (STI) has been a popular method for predicting speech intelligibility in rooms. It is based on the magnitude of the modulation transfer function, which can be derived from the impulse response of the room and the background noise levels. However, it does not take...

Development of an Improved Time Varying Loudness Model with the Inclusion of Binaural Loudness Summation

Science.gov (United States)

Charbonneau, Jeremy

As the perceived quality of a product is becoming more important in the manufacturing industry, more emphasis is being placed on accurately predicting the sound quality of everyday objects. This study was undertaken to improve upon current prediction techniques with regard to the psychoacoustic descriptor of loudness and an improved binaural summation technique. The feasibility of this project was first investigated through a loudness matching experiment involving thirty-one subjects and pure tones of constant sound pressure level. A dependence of binaural summation on frequency was observed which had previously not been a subject of investigation in the reviewed literature. A follow-up investigation was carried out with forty-eight volunteers and pure tones of constant sensation level. Contrary to existing theories in literature the resulting loudness matches revealed an amplitude versus frequency relationship which confirmed the perceived increase in loudness when a signal was presented to both ears simultaneously as opposed to one ear alone. The resulting trend strongly indicated that the higher the frequency of the presented signal, the greater the increase in observed binaural summation. The results from each investigation were summarized into a single binaural summation algorithm and inserted into an improved time-varying loudness model. Using experimental techniques, it was demonstrated that the updated binaural summation algorithm was a considerable improvement over the state of the art approach for predicting the perceived binaural loudness. The improved function retained the ease of use from the original model while additionally providing accurate estimates of diotic listening conditions from monaural WAV files. It was clearly demonstrated using a validation jury test that the revised time-varying loudness model was a significant improvement over the previously standardized approach.

An evaluation of the performance of two binaural beamformers in complex and dynamic multitalker environments.

Science.gov (United States)

Best, Virginia; Mejia, Jorge; Freeston, Katrina; van Hoesel, Richard J; Dillon, Harvey

2015-01-01

Binaural beamformers are super-directional hearing aids created by combining microphone outputs from each side of the head. While they offer substantial improvements in SNR over conventional directional hearing aids, the benefits (and possible limitations) of these devices in realistic, complex listening situations have not yet been fully explored. In this study we evaluated the performance of two experimental binaural beamformers. Testing was carried out using a horizontal loudspeaker array. Background noise was created using recorded conversations. Performance measures included speech intelligibility, localization in noise, acceptable noise level, subjective ratings, and a novel dynamic speech intelligibility measure. Participants were 27 listeners with bilateral hearing loss, fitted with BTE prototypes that could be switched between conventional directional or binaural beamformer microphone modes. Relative to the conventional directional microphones, both binaural beamformer modes were generally superior for tasks involving fixed frontal targets, but not always for situations involving dynamic target locations. Binaural beamformers show promise for enhancing listening in complex situations when the location of the source of interest is predictable.

Gender differences in binaural speech-evoked auditory brainstem response: are they clinically significant?

Science.gov (United States)

Jalaei, Bahram; Azmi, Mohd Hafiz Afifi Mohd; Zakaria, Mohd Normani

2018-05-17

Binaurally evoked auditory evoked potentials have good diagnostic values when testing subjects with central auditory deficits. The literature on speech-evoked auditory brainstem response evoked by binaural stimulation is in fact limited. Gender disparities in speech-evoked auditory brainstem response results have been consistently noted but the magnitude of gender difference has not been reported. The present study aimed to compare the magnitude of gender difference in speech-evoked auditory brainstem response results between monaural and binaural stimulations. A total of 34 healthy Asian adults aged 19-30 years participated in this comparative study. Eighteen of them were females (mean age=23.6±2.3 years) and the remaining sixteen were males (mean age=22.0±2.3 years). For each subject, speech-evoked auditory brainstem response was recorded with the synthesized syllable /da/ presented monaurally and binaurally. While latencies were not affected (p>0.05), the binaural stimulation produced statistically higher speech-evoked auditory brainstem response amplitudes than the monaural stimulation (p0.80), substantive gender differences were noted in most of speech-evoked auditory brainstem response peaks for both stimulation modes. The magnitude of gender difference between the two stimulation modes revealed some distinct patterns. Based on these clinically significant results, gender-specific normative data are highly recommended when using speech-evoked auditory brainstem response for clinical and future applications. The preliminary normative data provided in the present study can serve as the reference for future studies on this test among Asian adults. Copyright © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Short-Term Effects of Binaural Beats on EEG Power, Functional Connectivity, Cognition, Gait and Anxiety in Parkinson's Disease.

Science.gov (United States)

Gálvez, Gerardo; Recuero, Manuel; Canuet, Leonides; Del-Pozo, Francisco

2018-06-01

We applied rhythmic binaural sound to Parkinson's Disease (PD) patients to investigate its influence on several symptoms of this disease and on Electrophysiology (Electrocardiography and Electroencephalography (EEG)). We conducted a double-blind, randomized controlled study in which rhythmic binaural beats and control were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design). Patients ([Formula: see text], age [Formula: see text], stage I-III Hoehn & Yahr scale) participated in two sessions of sound stimulation for 10[Formula: see text]min separated by a minimum of 7 days. Data were collected immediately before and after both stimulations with the following results: (1) a decrease in theta activity, (2) a general decrease in Functional Connectivity (FC), and (3) an improvement in working memory performance. However, no significant changes were identified in the gait performance, heart rate or anxiety level of the patients. With regard to the control stimulation, we did not identify significant changes in the variables analyzed. The use of binaural-rhythm stimulation for PD, as designed in this study, seems to be an effective, portable, inexpensive and noninvasive method to modulate brain activity. This influence on brain activity did not induce changes in anxiety or gait parameters; however, it resulted in a normalization of EEG power (altered in PD), normalization of brain FC (also altered in PD) and working memory improvement (a normalizing effect). In summary, we consider that sound, particularly binaural-rhythmic sound, may be a co-assistant tool in the treatment of PD, however more research is needed to consider the use of this type of stimulation as an effective therapy.

Binaural pitch perception in normal-hearing and hearing-impaired listeners

DEFF Research Database (Denmark)

Santurette, Sébastien; Dau, Torsten

2007-01-01

The effects of hearing impairment on the perception of binaural-pitch stimuli were investigated. Several experiments were performed with normal-hearing and hearing-impaired listeners, including detection and discrimination of binaural pitch, and melody recognition using different types of binaural...... pitches. For the normal-hearing listeners, all types of binaural pitches could be perceived immediately and were musical. The hearing-impaired listeners could be divided into three groups based on their results: (a) some perceived all types of binaural pitches, but with decreased salience or musicality...... compared to normal-hearing listeners; (b) some could only perceive the strongest pitch types; (c) some were unable to perceive any binaural pitch at all. The performance of the listeners was not correlated with audibility. Additional experiments investigated the correlation between performance in binaural...

Binaural hearing with electrical stimulation

Science.gov (United States)

Kan, Alan; Litovsky, Ruth Y.

2014-01-01

Bilateral cochlear implantation is becoming a standard of care in many clinics. While much benefit has been shown through bilateral implantation, patients who have bilateral cochlear implants (CIs) still do not perform as well as normal hearing listeners in sound localization and understanding speech in noisy environments. This difference in performance can arise from a number of different factors, including the areas of hardware and engineering, surgical precision and pathology of the auditory system in deaf persons. While surgical precision and individual pathology are factors that are beyond careful control, improvements can be made in the areas of clinical practice and the engineering of binaural speech processors. These improvements should be grounded in a good understanding of the sensitivities of bilateral CI patients to the acoustic binaural cues that are important to normal hearing listeners for sound localization and speech in noise understanding. To this end, we review the current state-of-the-art in the understanding of the sensitivities of bilateral CI patients to binaural cues in electric hearing, and highlight the important issues and challenges as they relate to clinical practice and the development of new binaural processing strategies. PMID:25193553

Intracranial electroencephalography power and phase synchronization changes during monaural and binaural beat stimulation.

Science.gov (United States)

Becher, Ann-Katrin; Höhne, Marlene; Axmacher, Nikolai; Chaieb, Leila; Elger, Christian E; Fell, Juergen

2015-01-01

Auditory stimulation with monaural or binaural auditory beats (i.e. sine waves with nearby frequencies presented either to both ears or to each ear separately) represents a non-invasive approach to influence electrical brain activity. It is still unclear exactly which brain sites are affected by beat stimulation. In particular, an impact of beat stimulation on mediotemporal brain areas could possibly provide new options for memory enhancement or seizure control. Therefore, we examined how electroencephalography (EEG) power and phase synchronization are modulated by auditory stimulation with beat frequencies corresponding to dominant EEG rhythms based on intracranial recordings in presurgical epilepsy patients. Monaural and binaural beat stimuli with beat frequencies of 5, 10, 40 and 80 Hz and non-superposed control signals were administered with low amplitudes (60 dB SPL) and for short durations (5 s). EEG power was intracranially recorded from mediotemporal, temporo-basal and temporo-lateral and surface sites. Evoked and total EEG power and phase synchronization during beat vs. control stimulation were compared by the use of Bonferroni-corrected non-parametric label-permutation tests. We found that power and phase synchronization were significantly modulated by beat stimulation not only at temporo-basal, temporo-lateral and surface sites, but also at mediotemporal sites. Generally, more significant decreases than increases were observed. The most prominent power increases were seen after stimulation with monaural 40-Hz beats. The most pronounced power and synchronization decreases resulted from stimulation with monaural 5-Hz and binaural 80-Hz beats. Our results suggest that beat stimulation offers a non-invasive approach for the modulation of intracranial EEG characteristics. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Conductive hearing loss and bone conduction devices: restored binaural hearing?

Science.gov (United States)

Agterberg, Martijn J H; Hol, Myrthe K S; Cremers, Cor W R J; Mylanus, Emmanuel A M; van Opstal, John; Snik, Ad F M

2011-01-01

An important aspect of binaural hearing is the proper detection of interaural sound level differences and interaural timing differences. Assessments of binaural hearing were made in patients with acquired unilateral conductive hearing loss (UCHL, n = 11) or congenital UCHL (n = 10) after unilateral application of a bone conduction device (BCD), and in patients with bilateral conductive or mixed hearing loss after bilateral BCD application. Benefit (bilateral versus unilateral listening) was assessed by measuring directional hearing, compensation of the acoustic head shadow, binaural summation and binaural squelch. Measurements were performed after an acclimatization time of at least 10 weeks. Unilateral BCD application was beneficial, but there was less benefit in the patients with congenital UCHL as compared to patients with acquired UCHL. In adults with bilateral hearing loss, bilateral BCD application was clearly beneficial as compared to unilateral BCD application. Binaural summation was present, but binaural squelch could not be proven. To explain the poor results in the patients with congenital UCHL, two factors seemed to be important. First, a critical period in the development of binaural hearing might affect the binaural hearing abilities. Second, crossover stimulation, referring to additional stimulation of the cochlea contralateral to the BCD side, might deteriorate binaural hearing in patients with UCHL. Copyright © 2011 S. Karger AG, Basel.

Anatomy and physiology of binaural hearing.

Science.gov (United States)

Moore, D R

1991-01-01

Binaural hearing improves performance in most auditory tasks and is essential for some. This paper introduces the brain stem pathways and nuclei involved in binaural interaction and outlines some recent approaches to understanding binaural mechanisms. It also provides examples of basic science approaches to the effects of infant hearing loss on those pathways and mechanisms. Binaural interaction occurs primarily and almost simultaneously at three levels of the brain: the superior olivary complex (SOC), the nuclei of the lateral lemniscus (NLL) and the inferior colliculus (IC). The SOC derives its input from the anterior ventral cochlear nucleus (CN) through branching axons that innervate several SOC subdivisions on both sides of the brain. At least some of these anteroventral CN axons project on up to the contralateral NLL and IC. The IC and NLL also receive direct, major projections from the contralateral CN, via the dorsal and intermediate acoustic striae, and from the SOC bilaterally. The IC receives additional input from the NLL bilaterally, and is thus innervated by every nuclear group within the auditory brain stem. There is little evidence for strict, functional segregation in these binaural pathways, although subdivisions of the SOC appear to be predominantly involved in analysing either interaural time or level differences (ITD, ILD). ITD- and ILD-sensitive neurones are also found in abundance in the central IC. There is emerging evidence that binaural information is coupled with spectral cues derived from the outer ear in several auditory mid-brain regions [the NLL, the external IC and the superior colliculus (SC)] to produce topographic representations of auditory space. Throughout the higher auditory system the response of neurones to stimulation of each ear is either excitatory or inhibitory, and there is a spatial segregation of neurones receiving predominantly excitatory or inhibitory input from the ipsilateral ear in both the medial geniculate body

Control of earphone produced binaural signals

DEFF Research Database (Denmark)

Hammershøi, Dorte; Hoffmann, Pablo F.

2011-01-01

While most people keep a high attention to the significance of the binaural recording method, whether it is e.g. individual or non-individual (as e.g. artificial head recording), many pay less attention to the type of earphone used to reproduce the binaural signals, and to the accurate control...

Comparing Binaural Pre-processing Strategies II

Directory of Open Access Journals (Sweden)

Regina M. Baumgärtel

2015-12-01

Full Text Available Several binaural audio signal enhancement algorithms were evaluated with respect to their potential to improve speech intelligibility in noise for users of bilateral cochlear implants (CIs. 50% speech reception thresholds (SRT50 were assessed using an adaptive procedure in three distinct, realistic noise scenarios. All scenarios were highly nonstationary, complex, and included a significant amount of reverberation. Other aspects, such as the perfectly frontal target position, were idealized laboratory settings, allowing the algorithms to perform better than in corresponding real-world conditions. Eight bilaterally implanted CI users, wearing devices from three manufacturers, participated in the study. In all noise conditions, a substantial improvement in SRT50 compared to the unprocessed signal was observed for most of the algorithms tested, with the largest improvements generally provided by binaural minimum variance distortionless response (MVDR beamforming algorithms. The largest overall improvement in speech intelligibility was achieved by an adaptive binaural MVDR in a spatially separated, single competing talker noise scenario. A no-pre-processing condition and adaptive differential microphones without a binaural link served as the two baseline conditions. SRT50 improvements provided by the binaural MVDR beamformers surpassed the performance of the adaptive differential microphones in most cases. Speech intelligibility improvements predicted by instrumental measures were shown to account for some but not all aspects of the perceptually obtained SRT50 improvements measured in bilaterally implanted CI users.

A dynamic binaural synthesis system for investigation into situational awareness for truck drivers

DEFF Research Database (Denmark)

Christensen, Flemming; Møller, Anders Kalsgaard; Hammershøi, Dorte

2016-01-01

into the reason for this point to cognitive phenomena such as change blindness, where more visual information won’t help. For other professional vehicle operators such as pilots, auditory solutions adding to a higher situational awareness has proven valuable. This paper describes the development of a dynamic...... communicating over a network protocol (UDP) enabling distribution on several hardware devices. The modules are: Graphical user interface, head tracking server, truck tracking, and binaural synthesis module. The function of the individual modules as well as overall topology of the system will be presented...

Binaural auditory beats affect long-term memory.

Science.gov (United States)

Garcia-Argibay, Miguel; Santed, Miguel A; Reales, José M

2017-12-08

The presentation of two pure tones to each ear separately with a slight difference in their frequency results in the perception of a single tone that fluctuates in amplitude at a frequency that equals the difference of interaural frequencies. This perceptual phenomenon is known as binaural auditory beats, and it is thought to entrain electrocortical activity and enhance cognition functions such as attention and memory. The aim of this study was to determine the effect of binaural auditory beats on long-term memory. Participants (n = 32) were kept blind to the goal of the study and performed both the free recall and recognition tasks after being exposed to binaural auditory beats, either in the beta (20 Hz) or theta (5 Hz) frequency bands and white noise as a control condition. Exposure to beta-frequency binaural beats yielded a greater proportion of correctly recalled words and a higher sensitivity index d' in recognition tasks, while theta-frequency binaural-beat presentation lessened the number of correctly remembered words and the sensitivity index. On the other hand, we could not find differences in the conditional probability for recall given recognition between beta and theta frequencies and white noise, suggesting that the observed changes in recognition were due to the recollection component. These findings indicate that the presentation of binaural auditory beats can affect long-term memory both positively and negatively, depending on the frequency used.

Binaural hearing with electrical stimulation.

Science.gov (United States)

Kan, Alan; Litovsky, Ruth Y

2015-04-01

Bilateral cochlear implantation is becoming a standard of care in many clinics. While much benefit has been shown through bilateral implantation, patients who have bilateral cochlear implants (CIs) still do not perform as well as normal hearing listeners in sound localization and understanding speech in noisy environments. This difference in performance can arise from a number of different factors, including the areas of hardware and engineering, surgical precision and pathology of the auditory system in deaf persons. While surgical precision and individual pathology are factors that are beyond careful control, improvements can be made in the areas of clinical practice and the engineering of binaural speech processors. These improvements should be grounded in a good understanding of the sensitivities of bilateral CI patients to the acoustic binaural cues that are important to normal hearing listeners for sound localization and speech in noise understanding. To this end, we review the current state-of-the-art in the understanding of the sensitivities of bilateral CI patients to binaural cues in electric hearing, and highlight the important issues and challenges as they relate to clinical practice and the development of new binaural processing strategies. This article is part of a Special Issue entitled . Copyright © 2014 Elsevier B.V. All rights reserved.

Ocular vestibular evoked myogenic potentials in response to air-conducted 500 Hz short tones: Effect of stimulation procedure (monaural or binaural), age and gender.

Science.gov (United States)

Versino, Maurizio; Colnaghi, Silvia; Ranzani, Marina; Alloni, Roberto; Bolis, Carlotta; Sacco, Simone; Moglia, Arrigo; Callieco, Roberto

2015-01-01

The ocular vestibular myogenic potentials (oVEMP) can be elicited by monaural air-conducted sound stimulation, and are usually recorded from the contralateral eye. In clinical setting a binaural stimulation would save time and require less effort from the subjects. We evaluated the differences between monaural and binaural stimulation, and the possible effect of age and gender on oVEMP parameters. Air-conducted oVEMP were recorded by binaural and by monaural stimulation in a group of 54 normal subjects, aged from 12 to 83 years, and in 50 vestibular patients. From each side, we measured the latency of the N1 component, and the peak-to-peak N1-P1 amplitude. For both parameters we also computed the asymmetry ratio. In normal subjects binaural stimulation produced slightly larger responses than monaural stimulation; detectability, latency and amplitude ratio were the same for the two techniques. We found no differences related to gender, and the age-induced amplitude decline was likely to be negligible.oVEMP recorded not in an acute phase of their disorder, proved to be abnormal in about 20% of the patients, and the normal or abnormal findings obtained either with monaural or with binaural stimulation were always concordant. The oVEMP obtained after binaural and monaural stimulation are very similar, and they are largely independent from age and gender.

Hearing with Two Ears: Evidence for Cortical Binaural Interaction during Auditory Processing.

Science.gov (United States)

Henkin, Yael; Yaar-Soffer, Yifat; Givon, Lihi; Hildesheimer, Minka

2015-04-01

Integration of information presented to the two ears has been shown to manifest in binaural interaction components (BICs) that occur along the ascending auditory pathways. In humans, BICs have been studied predominantly at the brainstem and thalamocortical levels; however, understanding of higher cortically driven mechanisms of binaural hearing is limited. To explore whether BICs are evident in auditory event-related potentials (AERPs) during the advanced perceptual and postperceptual stages of cortical processing. The AERPs N1, P3, and a late negative component (LNC) were recorded from multiple site electrodes while participants performed an oddball discrimination task that consisted of natural speech syllables (/ka/ vs. /ta/) that differed by place-of-articulation. Participants were instructed to respond to the target stimulus (/ta/) while performing the task in three listening conditions: monaural right, monaural left, and binaural. Fifteen (21-32 yr) young adults (6 females) with normal hearing sensitivity. By subtracting the response to target stimuli elicited in the binaural condition from the sum of responses elicited in the monaural right and left conditions, the BIC waveform was derived and the latencies and amplitudes of the components were measured. The maximal interaction was calculated by dividing BIC amplitude by the summed right and left response amplitudes. In addition, the latencies and amplitudes of the AERPs to target stimuli elicited in the monaural right, monaural left, and binaural listening conditions were measured and subjected to analysis of variance with repeated measures testing the effect of listening condition and laterality. Three consecutive BICs were identified at a mean latency of 129, 406, and 554 msec, and were labeled N1-BIC, P3-BIC, and LNC-BIC, respectively. Maximal interaction increased significantly with progression of auditory processing from perceptual to postperceptual stages and amounted to 51%, 55%, and 75% of the sum of

Monaural Congenital Deafness Affects Aural Dominance and Degrades Binaural Processing

Science.gov (United States)

Tillein, Jochen; Hubka, Peter; Kral, Andrej

2016-01-01

Cortical development extensively depends on sensory experience. Effects of congenital monaural and binaural deafness on cortical aural dominance and representation of binaural cues were investigated in the present study. We used an animal model that precisely mimics the clinical scenario of unilateral cochlear implantation in an individual with single-sided congenital deafness. Multiunit responses in cortical field A1 to cochlear implant stimulation were studied in normal-hearing cats, bilaterally congenitally deaf cats (CDCs), and unilaterally deaf cats (uCDCs). Binaural deafness reduced cortical responsiveness and decreased response thresholds and dynamic range. In contrast to CDCs, in uCDCs, cortical responsiveness was not reduced, but hemispheric-specific reorganization of aural dominance and binaural interactions were observed. Deafness led to a substantial drop in binaural facilitation in CDCs and uCDCs, demonstrating the inevitable role of experience for a binaural benefit. Sensitivity to interaural time differences was more reduced in uCDCs than in CDCs, particularly at the hemisphere ipsilateral to the hearing ear. Compared with binaural deafness, unilateral hearing prevented nonspecific reduction in cortical responsiveness, but extensively reorganized aural dominance and binaural responses. The deaf ear remained coupled with the cortex in uCDCs, demonstrating a significant difference to deprivation amblyopia in the visual system. PMID:26803166

Monaural Congenital Deafness Affects Aural Dominance and Degrades Binaural Processing.

Science.gov (United States)

Tillein, Jochen; Hubka, Peter; Kral, Andrej

2016-04-01

Cortical development extensively depends on sensory experience. Effects of congenital monaural and binaural deafness on cortical aural dominance and representation of binaural cues were investigated in the present study. We used an animal model that precisely mimics the clinical scenario of unilateral cochlear implantation in an individual with single-sided congenital deafness. Multiunit responses in cortical field A1 to cochlear implant stimulation were studied in normal-hearing cats, bilaterally congenitally deaf cats (CDCs), and unilaterally deaf cats (uCDCs). Binaural deafness reduced cortical responsiveness and decreased response thresholds and dynamic range. In contrast to CDCs, in uCDCs, cortical responsiveness was not reduced, but hemispheric-specific reorganization of aural dominance and binaural interactions were observed. Deafness led to a substantial drop in binaural facilitation in CDCs and uCDCs, demonstrating the inevitable role of experience for a binaural benefit. Sensitivity to interaural time differences was more reduced in uCDCs than in CDCs, particularly at the hemisphere ipsilateral to the hearing ear. Compared with binaural deafness, unilateral hearing prevented nonspecific reduction in cortical responsiveness, but extensively reorganized aural dominance and binaural responses. The deaf ear remained coupled with the cortex in uCDCs, demonstrating a significant difference to deprivation amblyopia in the visual system. © The Author 2016. Published by Oxford University Press.

Binaural masking level differences in nonsimultanuous masking

NARCIS (Netherlands)

Kohlrausch, A.G.; Fassel, R.; Gilkey, R.H.; Anderson, T.R.

1997-01-01

This chapter investigates the extent to which binaural unmasking occurs with nonsimultaneous presentation of masker and signal, particularly in forward masking. The majority of previous studies that addressed this question found that there is a substantial binaural masking level difference (BMLD) in

Cortical evoked potentials to an auditory illusion: binaural beats.

Science.gov (United States)

Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

2009-08-01

To define brain activity corresponding to an auditory illusion of 3 and 6Hz binaural beats in 250Hz or 1000Hz base frequencies, and compare it to the sound onset response. Event-Related Potentials (ERPs) were recorded in response to unmodulated tones of 250 or 1000Hz to one ear and 3 or 6Hz higher to the other, creating an illusion of amplitude modulations (beats) of 3Hz and 6Hz, in base frequencies of 250Hz and 1000Hz. Tones were 2000ms in duration and presented with approximately 1s intervals. Latency, amplitude and source current density estimates of ERP components to tone onset and subsequent beats-evoked oscillations were determined and compared across beat frequencies with both base frequencies. All stimuli evoked tone-onset P(50), N(100) and P(200) components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude with the low base frequency and to the low beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left lateral and inferior temporal lobe areas in all stimulus conditions. Onset-evoked components were not different across stimulus conditions; P(50) had significantly different sources than the beats-evoked oscillations; and N(100) and P(200) sources located to the same temporal lobe regions as beats-evoked oscillations, but were bilateral and also included frontal and parietal contributions. Neural activity with slightly different volley frequencies from left and right ear converges and interacts in the central auditory brainstem pathways to generate beats of neural activity to modulate activities in the left temporal lobe, giving rise to the illusion of binaural beats. Cortical potentials recorded to binaural beats are distinct from onset responses. Brain activity corresponding to an auditory illusion of low frequency beats can be recorded from the scalp.

Pre- and Postoperative Binaural Unmasking for Bimodal Cochlear Implant Listeners.

Science.gov (United States)

Sheffield, Benjamin M; Schuchman, Gerald; Bernstein, Joshua G W

Cochlear implants (CIs) are increasingly recommended to individuals with residual bilateral acoustic hearing. Although new hearing-preserving electrode designs and surgical approaches show great promise, CI recipients are still at risk to lose acoustic hearing in the implanted ear, which could prevent the ability to take advantage of binaural unmasking to aid speech recognition in noise. This study examined the tradeoff between the benefits of a CI for speech understanding in noise and the potential loss of binaural unmasking for CI recipients with some bilateral preoperative acoustic hearing. Binaural unmasking is difficult to evaluate in CI candidates because speech perception in noise is generally too poor to measure reliably in the range of signal to noise ratios (SNRs) where binaural intelligibility level differences (BILDs) are typically observed (binaural benefit, 9 out of 10 listeners tested postoperatively had performance equal to or better than their best pre-CI performance. The listener who retained functional acoustic hearing in the implanted ear also demonstrated a preserved acoustic BILD postoperatively. Approximately half of the CI candidates in this study demonstrated preoperative binaural hearing benefits for audiovisual speech perception in noise. Most of these listeners lost their acoustic hearing in the implanted ear after surgery (using nonhearing-preservation techniques), and therefore lost access to this binaural benefit. In all but one case, any loss of binaural benefit was compensated for or exceeded by an improvement in speech perception with the CI. Evidence of a preoperative BILD suggests that certain CI candidates might further benefit from hearing-preservation surgery to retain acoustic binaural unmasking, as demonstrated for the listener who underwent hearing-preservation surgery. This test of binaural audiovisual speech perception in noise could serve as a diagnostic tool to identify CI candidates who are most likely to receive

Comparisons between Binaural In-situ Recordings and Auralizations

DEFF Research Database (Denmark)

Saher, Konca; Rindel, Jens Holger; Nijs, Lau

2006-01-01

-architectural design. This paper deals with comparison between binaural in-situ recordings and auralizations obtained from computer simulations. Listening tests and questionnaires were prepared from auralizations to compare with the reference binaural recordings. The difficulties in evaluation of auralization quality...... are discussed. The results indicate that although auralizations and binaural recordings evoke different aural perception auralization is a strong tool to assess the acoustical environment before the space is built. Two commercial programs are used for the auralizations. (ODEON and CATT-Acoustics)...

The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity.

Directory of Open Access Journals (Sweden)

Christine Beauchene

Full Text Available Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, have not been well studied. Furthermore, no studies have evaluated the effects of binaural beats on brain connectivity during working memory tasks. In this study, we determined the effects of different acoustic stimulation conditions on participant response accuracy and cortical network topology, as measured by EEG recordings, during a visuospatial working memory task. Three acoustic stimulation control conditions and three binaural beat stimulation conditions were used: None, Pure Tone, Classical Music, 5Hz binaural beats, 10Hz binaural beats, and 15Hz binaural beats. We found that listening to 15Hz binaural beats during a visuospatial working memory task not only increased the response accuracy, but also modified the strengths of the cortical networks during the task. The three auditory control conditions and the 5Hz and 10Hz binaural beats all decreased accuracy. Based on graphical network analyses, the cortical activity during 15Hz binaural beats produced networks characteristic of high information transfer with consistent connection strengths throughout the visuospatial working memory task.

The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity.

Science.gov (United States)

Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A; Leonessa, Alexander

2016-01-01

Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, have not been well studied. Furthermore, no studies have evaluated the effects of binaural beats on brain connectivity during working memory tasks. In this study, we determined the effects of different acoustic stimulation conditions on participant response accuracy and cortical network topology, as measured by EEG recordings, during a visuospatial working memory task. Three acoustic stimulation control conditions and three binaural beat stimulation conditions were used: None, Pure Tone, Classical Music, 5Hz binaural beats, 10Hz binaural beats, and 15Hz binaural beats. We found that listening to 15Hz binaural beats during a visuospatial working memory task not only increased the response accuracy, but also modified the strengths of the cortical networks during the task. The three auditory control conditions and the 5Hz and 10Hz binaural beats all decreased accuracy. Based on graphical network analyses, the cortical activity during 15Hz binaural beats produced networks characteristic of high information transfer with consistent connection strengths throughout the visuospatial working memory task.

Binaural interaction in auditory evoked potentials: Brainstem, middle- and long-latency components

OpenAIRE

McPherson, DL; Starr, A

1993-01-01

Binaural interaction occurs in the auditory evoked potentials when the sum of the monaural auditory evoked potentials are not equivalent to the binaural evoked auditory potentials. Binaural interaction of the early- (0-10 ms), middle- (10-50 ms) and long-latency (50-200 ms) auditory evoked potentials was studied in 17 normal young adults. For the early components, binaural interaction was maximal at 7.35 ms accounting for a reduction of 21% of the amplitude of the binaural evoked potentials. ...

Directional dependence of binaural loudness

DEFF Research Database (Denmark)

Ellermeier, Wolfgang; Sivonen, Ville Pekka

2006-01-01

on binaural loudness summation, on the other hand, focuses on a highly artificial paradigm according to which unnatural combinations of sound pressure levels(such as monotic-diotic comparisons) are presented to listeners via headphones. In order to reconcile these two approaches, we recently started a series...... incidence angle, in order to relate the changes in actual at-ear exposure to the observed changes in loudness as a function of sound incidence. Combining the listening-test data with the physical measurements, an attempt was made to model the binaural summation underlying the directional loudness matches....

Binaural pitch perception in hearing-impaired listeners

DEFF Research Database (Denmark)

Dau, Torsten; Santurette, Sébastien; Strelcyk, Olaf

2007-01-01

When two white noises differing only in phase in a particular frequency range are presented simultaneously each to one of our ears, a pitch sensation may be perceived inside the head. This phenomenon, called ’binaural pitch’ or ’dichotic pitch’, can be produced by frequency-dependent interaural...... phasedifference patterns. The evaluation of these interaural phase differences depends on the functionality of the binaural auditory system and the spectro-temporal information at its input. A melody recognition task was performed in the present study using pure-tone stimuli and six different types of noises...... that can generate a binaural pitch sensation. Normal-hearing listeners and hearing-impaired listeners with different kinds of hearing impairment participated in the experiment....

Binaural speech discrimination under noise in hearing-impaired listeners

Science.gov (United States)

Kumar, K. V.; Rao, A. B.

1988-01-01

This paper presents the results of an assessment of speech discrimination by hearing-impaired listeners (sensori-neural, conductive, and mixed groups) under binaural free-field listening in the presence of background noise. Subjects with pure-tone thresholds greater than 20 dB in 0.5, 1.0 and 2.0 kHz were presented with a version of the W-22 list of phonetically balanced words under three conditions: (1) 'quiet', with the chamber noise below 28 dB and speech at 60 dB; (2) at a constant S/N ratio of +10 dB, and with a background white noise at 70 dB; and (3) same as condition (2), but with the background noise at 80 dB. The mean speech discrimination scores decreased significantly with noise in all groups. However, the decrease in binaural speech discrimination scores with an increase in hearing impairment was less for material presented under the noise conditions than for the material presented in quiet.

Improved multi-microphone noise reduction preserving binaural cues

NARCIS (Netherlands)

Koutrouvelis, A.; Hendriks, R.C.; Jensen, J; Heusdens, R.; Dong, Min; Zheng, Thomas Fang

2016-01-01

We propose a new multi-microphone noise reduction technique for binaural cue preservation of the desired source and the interferers. This method is based on the linearly constrained minimum variance (LCMV) framework, where the constraints are used for the binaural cue preservation of the desired

A framework for testing and comparing binaural models.

Science.gov (United States)

Dietz, Mathias; Lestang, Jean-Hugues; Majdak, Piotr; Stern, Richard M; Marquardt, Torsten; Ewert, Stephan D; Hartmann, William M; Goodman, Dan F M

2018-03-01

Auditory research has a rich history of combining experimental evidence with computational simulations of auditory processing in order to deepen our theoretical understanding of how sound is processed in the ears and in the brain. Despite significant progress in the amount of detail and breadth covered by auditory models, for many components of the auditory pathway there are still different model approaches that are often not equivalent but rather in conflict with each other. Similarly, some experimental studies yield conflicting results which has led to controversies. This can be best resolved by a systematic comparison of multiple experimental data sets and model approaches. Binaural processing is a prominent example of how the development of quantitative theories can advance our understanding of the phenomena, but there remain several unresolved questions for which competing model approaches exist. This article discusses a number of current unresolved or disputed issues in binaural modelling, as well as some of the significant challenges in comparing binaural models with each other and with the experimental data. We introduce an auditory model framework, which we believe can become a useful infrastructure for resolving some of the current controversies. It operates models over the same paradigms that are used experimentally. The core of the proposed framework is an interface that connects three components irrespective of their underlying programming language: The experiment software, an auditory pathway model, and task-dependent decision stages called artificial observers that provide the same output format as the test subject. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of binaural microphones for externalization of sounds

DEFF Research Database (Denmark)

Cubick, Jens; Sánchez Rodríguez, C.; Song, Wookeun

2015-01-01

or with microphones placed inside the ear canals of a person. In this study, binaural room impulse responses (BRIRs) were measured with several commercially available binaural microphones, both placed inside the listeners’ ears (individual BRIR) and on a head and torso simulator (generic BRIR). The degree...

Binaural beats at high frequencies.

Science.gov (United States)

McFadden, D; Pasanen, E G

1975-10-24

Binaural beats have long been believed to be audible only at low frequencies, but an interaction reminiscent of a binaural beat can sometimes be heard when different two-tone complexes of high frequency are presented to the two ears. The primary requirement is that the frequency separation in the complex at one ear be slightly different from that in the other--that is, that there be a small interaural difference in the envelope periodicities. This finding is in accord with other recent demonstrations that the auditory system is not deaf to interaural time differences at high frequencies.

A prospective, randomised, controlled study examining binaural beat audio and pre-operative anxiety in patients undergoing general anaesthesia for day case surgery.

Science.gov (United States)

Padmanabhan, R; Hildreth, A J; Laws, D

2005-09-01

Pre-operative anxiety is common and often significant. Ambulatory surgery challenges our pre-operative goal of an anxiety-free patient by requiring people to be 'street ready' within a brief period of time after surgery. Recently, it has been demonstrated that music can be used successfully to relieve patient anxiety before operations, and that audio embedded with tones that create binaural beats within the brain of the listener decreases subjective levels of anxiety in patients with chronic anxiety states. We measured anxiety with the State-Trait Anxiety Inventory questionnaire and compared binaural beat audio (Binaural Group) with an identical soundtrack but without these added tones (Audio Group) and with a third group who received no specific intervention (No Intervention Group). Mean [95% confidence intervals] decreases in anxiety scores were 26.3%[19-33%] in the Binaural Group (p = 0.001 vs. Audio Group, p Binaural beat audio has the potential to decrease acute pre-operative anxiety significantly.

Binaural masking release in children with Down syndrome.

Science.gov (United States)

Porter, Heather L; Grantham, D Wesley; Ashmead, Daniel H; Tharpe, Anne Marie

2014-01-01

Binaural hearing results in a number of listening advantages relative to monaural hearing, including enhanced hearing sensitivity and better speech understanding in adverse listening conditions. These advantages are facilitated in part by the ability to detect and use interaural cues within the central auditory system. Binaural hearing for children with Down syndrome could be impacted by multiple factors including, structural anomalies within the peripheral and central auditory system, alterations in synaptic communication, and chronic otitis media with effusion. However, binaural hearing capabilities have not been investigated in these children. This study tested the hypothesis that children with Down syndrome experience less binaural benefit than typically developing peers. Participants included children with Down syndrome aged 6 to 16 years (n = 11), typically developing children aged 3 to 12 years (n = 46), adults with Down syndrome (n = 3), and adults with no known neurological delays (n = 6). Inclusionary criteria included normal to near-normal hearing sensitivity. Two tasks were used to assess binaural ability. Masking level difference (MLD) was calculated by comparing threshold for a 500-Hz pure-tone signal in 300-Hz wide Gaussian noise for N0S0 and N0Sπ signal configurations. Binaural intelligibility level difference was calculated using simulated free-field conditions. Speech recognition threshold was measured for closed-set spondees presented from 0-degree azimuth in speech-shaped noise presented from 0-, 45- and 90-degree azimuth, respectively. The developmental ability of children with Down syndrome was estimated and information regarding history of otitis media was obtained for all child participants via parent survey. Individuals with Down syndrome had higher masked thresholds for pure-tone and speech stimuli than typically developing individuals. Children with Down syndrome had significantly smaller MLDs than typically developing children. Adults

Individual Differences in Behavioral and Electrophysiological Measures of Binaural Processing Across the Adult Life Span.

Science.gov (United States)

Roup, Christina M; Leigh, Elizabeth D

2015-06-01

The purpose of the present study was to examine individual differences in binaural processing across the adult life span. Sixty listeners (aged 23-80 years) with symmetrical hearing were tested. Binaural behavioral processing was measured by the Words-in-Noise Test, the 500-Hz masking level difference, and the Dichotic Digit Test. Electrophysiologic responses were assessed by the auditory middle latency response binaural interaction component. No correlations among binaural measures were found. Age accounted for the greatest amount of variability in speech-in-noise performance. Age was significantly correlated with the Words-in-Noise Test binaural advantage and dichotic ear advantage. Partial correlations, however, revealed that this was an effect of hearing status rather than age per se. Inspection of individual results revealed that 20% of listeners demonstrated reduced binaural performance for at least 2 of the binaural measures. The lack of significant correlations among variables suggests that each is an important measurement of binaural abilities. For some listeners, binaural processing was abnormal, reflecting a binaural processing deficit not identified by monaural audiologic tests. The inclusion of a binaural test battery in the audiologic evaluation is supported given that these listeners may benefit from alternative forms of audiologic rehabilitation.

The role of reverberation-related binaural cues in the externalization of speech.

Science.gov (United States)

Catic, Jasmina; Santurette, Sébastien; Dau, Torsten

2015-08-01

The perception of externalization of speech sounds was investigated with respect to the monaural and binaural cues available at the listeners' ears in a reverberant environment. Individualized binaural room impulse responses (BRIRs) were used to simulate externalized sound sources via headphones. The measured BRIRs were subsequently modified such that the proportion of the response containing binaural vs monaural information was varied. Normal-hearing listeners were presented with speech sounds convolved with such modified BRIRs. Monaural reverberation cues were found to be sufficient for the externalization of a lateral sound source. In contrast, for a frontal source, an increased amount of binaural cues from reflections was required in order to obtain well externalized sound images. It was demonstrated that the interaction between the interaural cues of the direct sound and the reverberation strongly affects the perception of externalization. An analysis of the short-term binaural cues showed that the amount of fluctuations of the binaural cues corresponded well to the externalization ratings obtained in the listening tests. The results further suggested that the precedence effect is involved in the auditory processing of the dynamic binaural cues that are utilized for externalization perception.

Clinical applications of selected binaural effects.

Science.gov (United States)

Noffsinger, D

1982-01-01

Examination was made of the behaviors exhibited on selected binaural tasks by 556 persons with diagnosed peripheral hearing loss or central nervous system damage. The tasks used included loudness balancing (LB), intracranial midline imaging (MI), masking level differences (MLD), and binaural beats (BB). The methods used were chosen for their clinical utility. Loudness balancing and midline imaging were of the most diagnostic value when hearing loss was present. Masking level differences were best at detecting pathology which did not produce hearing loss. None of the techniques were sensitive to cortical damage.

Differences in binaural interaction at low and high frequencies

NARCIS (Netherlands)

Par, van de S.L.J.D.E.; Kohlrausch, A.G.

1993-01-01

Differences in the acoustic signals received by both ears form the major basis of our ability to localize sound sources. They can also help in detecting a signal against a background of interfering (masking) sounds. A quantitative measure for this 'binaural advantage' is the Binaural Masking Level

Availability of binaural cues for pediatric bilateral cochlear implant recipients.

Science.gov (United States)

Sheffield, Sterling W; Haynes, David S; Wanna, George B; Labadie, Robert F; Gifford, René H

2015-03-01

Bilateral implant recipients theoretically have access to binaural cues. Research in postlingually deafened adults with cochlear implants (CIs) indicates minimal evidence for true binaural hearing. Congenitally deafened children who experience spatial hearing with bilateral CIs, however, might perceive binaural cues in the CI signal differently. There is limited research examining binaural hearing in children with CIs, and the few published studies are limited by the use of unrealistic speech stimuli and background noise. The purposes of this study were to (1) replicate our previous study of binaural hearing in postlingually deafened adults with AzBio sentences in prelingually deafened children with the pediatric version of the AzBio sentences, and (2) replicate previous studies of binaural hearing in children with CIs using more open-set sentences and more realistic background noise (i.e., multitalker babble). The study was a within-participant, repeated-measures design. The study sample consisted of 14 children with bilateral CIs with at least 25 mo of listening experience. Speech recognition was assessed using sentences presented in multitalker babble at a fixed signal-to-noise ratio. Test conditions included speech at 0° with noise presented at 0° (S0N0), on the side of the first CI (90° or 270°) (S0N1stCI), and on the side of the second CI (S0N2ndCI) as well as speech presented at 0° with noise presented semidiffusely from eight speakers at 45° intervals. Estimates of summation, head shadow, squelch, and spatial release from masking were calculated. Results of test conditions commonly reported in the literature (S0N0, S0N1stCI, S0N2ndCI) are consistent with results from previous research in adults and children with bilateral CIs, showing minimal summation and squelch but typical head shadow and spatial release from masking. However, bilateral benefit over the better CI with speech at 0° was much larger with semidiffuse noise. Congenitally deafened

Binaural integration: a challenge to overcome for children with hearing loss.

Science.gov (United States)

Gordon, Karen A; Cushing, Sharon L; Easwar, Vijayalakshmi; Polonenko, Melissa J; Papsin, Blake C

2017-12-01

Access to bilateral hearing can be provided to children with hearing loss by fitting appropriate hearing devices to each affected ear. It is not clear, however, that bilateral input is properly integrated through hearing devices to promote binaural hearing. In the present review, we examine evidence indicating that abnormal binaural hearing continues to be a challenge for children with hearing loss despite early access to bilateral input. Behavioral responses and electrophysiological data in children, combined with data from developing animal models, reveal that deafness in early life disrupts binaural hearing and that present hearing devices are unable to reverse these changes and/or promote expected development. Possible limitations of hearing devices include mismatches in binaural place, level, and timing of stimulation. Such mismatches could be common in children with hearing loss. One potential solution is to modify present device fitting beyond providing audibility to each ear by implementing binaural fitting targets. Efforts to better integrate bilateral input could improve spatial hearing in children with hearing loss.

Combination of Adaptive Feedback Cancellation and Binaural Adaptive Filtering in Hearing Aids

Directory of Open Access Journals (Sweden)

Anthony Lombard

2009-01-01

Full Text Available We study a system combining adaptive feedback cancellation and adaptive filtering connecting inputs from both ears for signal enhancement in hearing aids. For the first time, such a binaural system is analyzed in terms of system stability, convergence of the algorithms, and possible interaction effects. As major outcomes of this study, a new stability condition adapted to the considered binaural scenario is presented, some already existing and commonly used feedback cancellation performance measures for the unilateral case are adapted to the binaural case, and possible interaction effects between the algorithms are identified. For illustration purposes, a blind source separation algorithm has been chosen as an example for adaptive binaural spatial filtering. Experimental results for binaural hearing aids confirm the theoretical findings and the validity of the new measures.

Binaural Beat: A Failure to Enhance EEG Power and Emotional Arousal

Directory of Open Access Journals (Sweden)

Fran López-Caballero

2017-11-01

Full Text Available When two pure tones of slightly different frequencies are delivered simultaneously to the two ears, is generated a beat whose frequency corresponds to the frequency difference between them. That beat is known as acoustic beat. If these two tones are presented one to each ear, they still produce the sensation of the same beat, although no physical combination of the tones occurs outside the auditory system. This phenomenon is called binaural beat. In the present study, we explored the potential contribution of binaural beats to the enhancement of specific electroencephalographic (EEG bands, as previous studies suggest the potential usefulness of binaural beats as a brainwave entrainment tool. Additionally, we analyzed the effects of binaural-beat stimulation on two psychophysiological measures related to emotional arousal: heart rate and skin conductance. Beats of five different frequencies (4.53 Hz -theta-, 8.97 Hz -alpha-, 17.93 Hz -beta-, 34.49 Hz -gamma- or 57.3 Hz -upper-gamma were presented binaurally and acoustically for epochs of 3 min (Beat epochs, preceded and followed by pink noise epochs of 90 s (Baseline and Post epochs, respectively. In each of these epochs, we analyzed the EEG spectral power, as well as calculated the heart rate and skin conductance response (SCR. For all the beat frequencies used for stimulation, no significant changes between Baseline and Beat epochs were observed within the corresponding EEG bands, neither with binaural or with acoustic beats. Additional analysis of spectral EEG topographies yielded negative results for the effect of binaural beats in the scalp distribution of EEG spectral power. In the psychophysiological measures, no changes in heart rate and skin conductance were observed for any of the beat frequencies presented. Our results do not support binaural-beat stimulation as a potential tool for the enhancement of EEG oscillatory activity, nor to induce changes in emotional arousal.

Binaural Beat: A Failure to Enhance EEG Power and Emotional Arousal.

Science.gov (United States)

López-Caballero, Fran; Escera, Carles

2017-01-01

When two pure tones of slightly different frequencies are delivered simultaneously to the two ears, is generated a beat whose frequency corresponds to the frequency difference between them. That beat is known as acoustic beat. If these two tones are presented one to each ear, they still produce the sensation of the same beat, although no physical combination of the tones occurs outside the auditory system. This phenomenon is called binaural beat. In the present study, we explored the potential contribution of binaural beats to the enhancement of specific electroencephalographic (EEG) bands, as previous studies suggest the potential usefulness of binaural beats as a brainwave entrainment tool. Additionally, we analyzed the effects of binaural-beat stimulation on two psychophysiological measures related to emotional arousal: heart rate and skin conductance. Beats of five different frequencies (4.53 Hz -theta-, 8.97 Hz -alpha-, 17.93 Hz -beta-, 34.49 Hz -gamma- or 57.3 Hz -upper-gamma) were presented binaurally and acoustically for epochs of 3 min (Beat epochs), preceded and followed by pink noise epochs of 90 s (Baseline and Post epochs, respectively). In each of these epochs, we analyzed the EEG spectral power, as well as calculated the heart rate and skin conductance response (SCR). For all the beat frequencies used for stimulation, no significant changes between Baseline and Beat epochs were observed within the corresponding EEG bands, neither with binaural or with acoustic beats. Additional analysis of spectral EEG topographies yielded negative results for the effect of binaural beats in the scalp distribution of EEG spectral power. In the psychophysiological measures, no changes in heart rate and skin conductance were observed for any of the beat frequencies presented. Our results do not support binaural-beat stimulation as a potential tool for the enhancement of EEG oscillatory activity, nor to induce changes in emotional arousal.

A high-density EEG investigation into steady state binaural beat stimulation.

Directory of Open Access Journals (Sweden)

Peter Goodin

Full Text Available Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz or Beta (16 Hz frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others.

A high-density EEG investigation into steady state binaural beat stimulation.

Science.gov (United States)

Goodin, Peter; Ciorciari, Joseph; Baker, Kate; Carey, Anne-Marie; Carrey, Anne-Marie; Harper, Michelle; Kaufman, Jordy

2012-01-01

Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz) or Beta (16 Hz) frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others.

More attentional focusing through binaural beats: evidence from the global-local task.

Science.gov (United States)

Colzato, Lorenza S; Barone, Hayley; Sellaro, Roberta; Hommel, Bernhard

2017-01-01

A recent study showed that binaural beats have an impact on the efficiency of allocating attention over time. We were interested to see whether this impact affects attentional focusing or, even further, the top-down control over irrelevant information. Healthy adults listened to gamma-frequency (40 Hz) binaural beats, which are assumed to increase attentional concentration, or a constant tone of 340 Hz (control condition) for 3 min before and during a global-local task. While the size of the congruency effect (indicating the failure to suppress task-irrelevant information) was unaffected by the binaural beats, the global-precedence effect (reflecting attentional focusing) was considerably smaller after gamma-frequency binaural beats than after the control condition. Our findings suggest that high-frequency binaural beats bias the individual attentional processing style towards a reduced spotlight of attention.

How to quantify binaural hearing in patients with unilateral hearing using hearing implants.

Science.gov (United States)

Snik, Ad; Agterberg, Martijn; Bosman, Arjan

2015-01-01

Application of bilateral hearing devices in bilateral hearing loss and unilateral application in unilateral hearing loss (second ear with normal hearing) does not a priori lead to binaural hearing. An overview is presented on several measures of binaural benefits that have been used in patients with unilateral or bilateral deafness using one or two cochlear implants, respectively, and in patients with unilateral or bilateral conductive/mixed hearing loss using one or two percutaneous bone conduction implants (BCDs), respectively. Overall, according to this overview, the most significant and sensitive measure is the benefit in directional hearing. Measures using speech (viz. binaural summation, binaural squelch or use of the head shadow effect) showed minor benefits, except for patients with bilateral conductive/mixed hearing loss using two BCDs. Although less feasible in daily practise, the binaural masking level difference test seems to be a promising option in the assessment of binaural function. © 2015 S. Karger AG, Basel.

Binaural Rendering in MPEG Surround

Directory of Open Access Journals (Sweden)

Kristofer Kjörling

2008-04-01

Full Text Available This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate “binaural parameters” that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

Human auditory steady state responses to binaural and monaural beats.

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Schwarz, D W F; Taylor, P

2005-03-01

Binaural beat sensations depend upon a central combination of two different temporally encoded tones, separately presented to the two ears. We tested the feasibility to record an auditory steady state evoked response (ASSR) at the binaural beat frequency in order to find a measure for temporal coding of sound in the human EEG. We stimulated each ear with a distinct tone, both differing in frequency by 40Hz, to record a binaural beat ASSR. As control, we evoked a beat ASSR in response to both tones in the same ear. We band-pass filtered the EEG at 40Hz, averaged with respect to stimulus onset and compared ASSR amplitudes and phases, extracted from a sinusoidal non-linear regression fit to a 40Hz period average. A 40Hz binaural beat ASSR was evoked at a low mean stimulus frequency (400Hz) but became undetectable beyond 3kHz. Its amplitude was smaller than that of the acoustic beat ASSR, which was evoked at low and high frequencies. Both ASSR types had maxima at fronto-central leads and displayed a fronto-occipital phase delay of several ms. The dependence of the 40Hz binaural beat ASSR on stimuli at low, temporally coded tone frequencies suggests that it may objectively assess temporal sound coding ability. The phase shift across the electrode array is evidence for more than one origin of the 40Hz oscillations. The binaural beat ASSR is an evoked response, with novel diagnostic potential, to a signal that is not present in the stimulus, but generated within the brain.

Effect of efferent activation on binaural frequency selectivity.

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Verhey, Jesko L; Kordus, Monika; Drga, Vit; Yasin, Ifat

2017-07-01

Binaural notched-noise experiments indicate a reduced frequency selectivity of the binaural system compared to monaural processing. The present study investigates how auditory efferent activation (via the medial olivocochlear system) affects binaural frequency selectivity in normal-hearing listeners. Thresholds were measured for a 1-kHz signal embedded in a diotic notched-noise masker for various notch widths. The signal was either presented in phase (diotic) or in antiphase (dichotic), gated with the noise. Stimulus duration was 25 ms, in order to avoid efferent activation due to the masker or the signal. A bandpass-filtered noise precursor was presented prior to the masker and signal stimuli to activate the efferent system. The silent interval between the precursor and the masker-signal complex was 50 ms. For comparison, thresholds for detectability of the masked signal were also measured in a baseline condition without the precursor and, in addition, without the masker. On average, the results of the baseline condition indicate an effectively wider binaural filter, as expected. For both signal phases, the addition of the precursor results in effectively wider filters, which is in agreement with the hypothesis that cochlear gain is reduced due to the presence of the precursor. Copyright © 2017 Elsevier B.V. All rights reserved.

Aural assessment by means of binaural algorithms -the AABBA project-

NARCIS (Netherlands)

Blauert, J.; Braasch, J.; Buchholz, J.; Colburn, H.S.; Jekosch, U.; Kohlrausch, A.G.; Mourjopoulos, J.; Pulkki, V.; Raake, A.; Buchholz, J.; Dau, T.; Christensen-Dalsgaard, J.; Poulsen, T.

2010-01-01

AABBA is an intellectual grouping with the goal of collaborating for 4-5 years on the application of computational models of human binaural hearing. The grouping will compile a battery of common software components for setting-up dedicated full-scale binaural models for various technological

Spectral and binaural loudness summation for hearing-impaired listeners.

Science.gov (United States)

Oetting, Dirk; Hohmann, Volker; Appell, Jens-E; Kollmeier, Birger; Ewert, Stephan D

2016-05-01

Sensorineural hearing loss typically results in a steepened loudness function and a reduced dynamic range from elevated thresholds to uncomfortably loud levels for narrowband and broadband signals. Restoring narrowband loudness perception for hearing-impaired (HI) listeners can lead to overly loud perception of broadband signals and it is unclear how binaural presentation affects loudness perception in this case. Here, loudness perception quantified by categorical loudness scaling for nine normal-hearing (NH) and ten HI listeners was compared for signals with different bandwidth and different spectral shape in monaural and in binaural conditions. For the HI listeners, frequency- and level-dependent amplification was used to match the narrowband monaural loudness functions of the NH listeners. The average loudness functions for NH and HI listeners showed good agreement for monaural broadband signals. However, HI listeners showed substantially greater loudness for binaural broadband signals than NH listeners: on average a 14.1 dB lower level was required to reach "very loud" (range 30.8 to -3.7 dB). Overall, with narrowband loudness compensation, a given binaural loudness for broadband signals above "medium loud" was reached at systematically lower levels for HI than for NH listeners. Such increased binaural loudness summation was not found for loudness categories below "medium loud" or for narrowband signals. Large individual variations in the increased loudness summation were observed and could not be explained by the audiogram or the narrowband loudness functions. Copyright © 2016 Elsevier B.V. All rights reserved.

Listening to Sentences in Noise: Revealing Binaural Hearing Challenges in Patients with Schizophrenia.

Science.gov (United States)

Abdul Wahab, Noor Alaudin; Zakaria, Mohd Normani; Abdul Rahman, Abdul Hamid; Sidek, Dinsuhaimi; Wahab, Suzaily

2017-11-01

The present, case-control, study investigates binaural hearing performance in schizophrenia patients towards sentences presented in quiet and noise. Participants were twenty-one healthy controls and sixteen schizophrenia patients with normal peripheral auditory functions. The binaural hearing was examined in four listening conditions by using the Malay version of hearing in noise test. The syntactically and semantically correct sentences were presented via headphones to the randomly selected subjects. In each condition, the adaptively obtained reception thresholds for speech (RTS) were used to determine RTS noise composite and spatial release from masking. Schizophrenia patients demonstrated significantly higher mean RTS value relative to healthy controls (p=0.018). The large effect size found in three listening conditions, i.e., in quiet (d=1.07), noise right (d=0.88) and noise composite (d=0.90) indicates statistically significant difference between the groups. However, noise front and noise left conditions show medium (d=0.61) and small (d=0.50) effect size respectively. No statistical difference between groups was noted in regards to spatial release from masking on right (p=0.305) and left (p=0.970) ear. The present findings suggest an abnormal unilateral auditory processing in central auditory pathway in schizophrenia patients. Future studies to explore the role of binaural and spatial auditory processing were recommended.

Consequences of Early Conductive Hearing Loss on Long-Term Binaural Processing.

Science.gov (United States)

Graydon, Kelley; Rance, Gary; Dowell, Richard; Van Dun, Bram

The aim of the study was to investigate the long-term effects of early conductive hearing loss on binaural processing in school-age children. One hundred and eighteen children participated in the study, 82 children with a documented history of conductive hearing loss associated with otitis media and 36 controls who had documented histories showing no evidence of otitis media or conductive hearing loss. All children were demonstrated to have normal-hearing acuity and middle ear function at the time of assessment. The Listening in Spatialized Noise Sentence (LiSN-S) task and the masking level difference (MLD) task were used as the two different measures of binaural interaction ability. Children with a history of conductive hearing loss performed significantly poorer than controls on all LiSN-S conditions relying on binaural cues (DV90, p = binaural cues. Fifteen children with a conductive hearing loss history (18%) showed results consistent with a spatial processing disorder. No significant difference was observed between the conductive hearing loss group and the controls on the MLD task. Furthermore, no correlations were found between LiSN-S and MLD. Results show a relationship between early conductive hearing loss and listening deficits that persist once hearing has returned to normal. Results also suggest that the two binaural interaction tasks (LiSN-S and MLD) may be measuring binaural processing at different levels. Findings highlight the need for a screening measure of functional listening ability in children with a history of early otitis media.

An introduction to binaural processing

NARCIS (Netherlands)

Kohlrausch, A.G.; Braasch, J.; Kolossa, D.; Blauert, J.; Blauert, J.

2013-01-01

The binaural auditory system performs a number of astonishing functions, such as precise localization of sound sources, analysis of auditory scenes, segregation of auditory streams, providing situational awareness in reflective environments, suppression of reverberance, noise and coloration,

Models of the electrically stimulated binaural system: A review.

Science.gov (United States)

Dietz, Mathias

2016-01-01

In an increasing number of countries, the standard treatment for deaf individuals is moving toward the implantation of two cochlear implants. Today's device technology and fitting procedure, however, appears as if the two implants would serve two independent ears and brains. Many experimental studies have demonstrated that after careful matching and balancing of left and right stimulation in controlled laboratory studies most patients have almost normal sensitivity to interaural level differences and some sensitivity to interaural time differences (ITDs). Mechanisms underlying the limited ITD sensitivity are still poorly understood and many different aspects may contribute. Recent pioneering computational approaches identified some of the functional implications the electric input imposes on the neural brainstem circuits. Simultaneously these studies have raised new questions and certainly demonstrated that further refinement of the model stages is necessary. They join the experimental study's conclusions that binaural device technology, binaural fitting, specific speech coding strategies, and binaural signal processing algorithms are obviously missing components to maximize the benefit of bilateral implantation. Within this review, the existing models of the electrically stimulated binaural system are explained, compared, and discussed from a viewpoint of a "CI device with auditory system" and from that of neurophysiological research.

Binaural hearing in children using Gaussian enveloped and transposed tones.

Science.gov (United States)

Ehlers, Erica; Kan, Alan; Winn, Matthew B; Stoelb, Corey; Litovsky, Ruth Y

2016-04-01

Children who use bilateral cochlear implants (BiCIs) show significantly poorer sound localization skills than their normal hearing (NH) peers. This difference has been attributed, in part, to the fact that cochlear implants (CIs) do not faithfully transmit interaural time differences (ITDs) and interaural level differences (ILDs), which are known to be important cues for sound localization. Interestingly, little is known about binaural sensitivity in NH children, in particular, with stimuli that constrain acoustic cues in a manner representative of CI processing. In order to better understand and evaluate binaural hearing in children with BiCIs, the authors first undertook a study on binaural sensitivity in NH children ages 8-10, and in adults. Experiments evaluated sound discrimination and lateralization using ITD and ILD cues, for stimuli with robust envelope cues, but poor representation of temporal fine structure. Stimuli were spondaic words, Gaussian-enveloped tone pulse trains (100 pulse-per-second), and transposed tones. Results showed that discrimination thresholds in children were adult-like (15-389 μs for ITDs and 0.5-6.0 dB for ILDs). However, lateralization based on the same binaural cues showed higher variability than seen in adults. Results are discussed in the context of factors that may be responsible for poor representation of binaural cues in bilaterally implanted children.

A binaural beat constructed from a noise

Science.gov (United States)

Akeroyd, Michael A

2012-01-01

The binaural beat has been used for over one hundred years as a stimulus for generating the percept of motion. Classically the beat consists of a pure tone at one ear (e.g. 500 Hz) and the same pure tone at the other ear but shifted upwards or downwards in frequency (e.g., 501 Hz). An experiment and binaural computational analysis are reported which demonstrate that a more powerful motion percept can be obtained by applying the concept of the frequency shift to a noise, via an upwards or downwards shift in the frequency of the Fourier components of its spectrum. PMID:21218863

Low bandwidth binaural beamforming

NARCIS (Netherlands)

Srinivasan, S.

2008-01-01

An efficient beamforming scheme for wireless binaural hearing aids is proposed that provides a trade-off between the transmission bit rate and the amount of noise reduction. It is proposed to transmit only the low-frequency part of the signal from one hearing aid to the other, which is used in a

The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity

OpenAIRE

Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A.; Leonessa, Alexander

2016-01-01

Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, hav...

Healthcare performance and the effects of the binaural beats on human blood pressure and heart rate.

Science.gov (United States)

Carter, Calvin

2008-01-01

Binaural beats are the differences in two different frequencies (in the range of 30-1000 Hz). Binaural beats are played through headphones and are perceived by the superior olivary nucleus of each hemisphere of the brain. The brain perceives the binaural beat and resonates to its frequency (frequency following response). Once the brain is in tune with the binaural beat it produces brainwaves of that frequency altering the listener's state of mind. In this experiment, the effects of the beta and theta binaural beat on human blood pressure and pulse were studied. Using headphones, three sounds were played for 7 minutes each to 12 participants: the control,- the sound of a babbling brook (the background sound to the two binaural beats), the beta binaural beat (20 Hz), and the theta binaural beat (7 Hz). Blood pressure and pulse were recorded before and after each sound was played. Each participant was given 2 minutes in-between each sound. The results showed that the control and the two binaural beats did not affect the 12 participant's blood pressure or pulse (p > 0.05). One reason for this may be that the sounds were not played long enough for the brain to either perceive and/or resonate to the frequency. Another reason why the sounds did not affect blood pressure and pulse may be due to the participant's age since older brains may not perceive the binaural beats as well as younger brains.

Brain responses to 40-Hz binaural beat and effects on emotion and memory.

Science.gov (United States)

Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

2017-10-01

Gamma oscillation plays a role in binding process or sensory integration, a process by which several brain areas beside primary cortex are activated for higher perception of the received stimulus. Beta oscillation is also involved in interpreting received stimulus and occurs following gamma oscillation, and this process is known as gamma-to-beta transition, a process for neglecting unnecessary stimuli in surrounding environment. Gamma oscillation also associates with cognitive functions, memory and emotion. Therefore, modulation of the brain activity can lead to manipulation of cognitive functions. The stimulus used in this study was 40-Hz binaural beat because binaural beat induces frequency following response. This study aimed to investigate the neural oscillation responding to the 40-Hz binaural beat and to evaluate working memory function and emotional states after listening to that stimulus. Two experiments were developed based on the study aims. In the first experiment, electroencephalograms were recorded while participants listened to the stimulus for 30min. The results suggested that frontal, temporal, and central regions were activated within 15min. In the second experiment, word list recall task was conducted before and after listening to the stimulus for 20min. The results showed that, after listening, the recalled words were increase in the working memory portion of the list. Brunel Mood Scale, a questionnaire to evaluate emotional states, revealed changes in emotional states after listening to the stimulus. The emotional results suggested that these changes were consistent with the induced neural oscillations. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterizing the monaural and binaural processes underlying reflection masking

DEFF Research Database (Denmark)

Buchholz, Jörg

2007-01-01

for the two RMTs, it is shown that forward masking effects only have a significant effect on reflection masking for delays above 7–10 ms. Moreover, binaural mechanisms were revealed which deteriorate auditory detection of test reflections for delays below 7–10 ms and enhance detection for larger delays....... The monaural and binaural processes that may underlie reflection masking are discussed in terms of auditory-modelling concepts....

The role of reverberation-related binaural cues in the externalization of speech

DEFF Research Database (Denmark)

Catic, Jasmina; Santurette, Sébastien; Dau, Torsten

2015-01-01

The perception of externalization of speech sounds was investigated with respect to the monaural and binaural cues available at the listeners’ ears in a reverberant environment. Individualized binaural room impulse responses (BRIRs) were used to simulate externalized sound sources via headphones....... The measured BRIRs were subsequently modified such that the proportion of the response containing binaural vs monaural information was varied. Normal-hearing listeners were presented with speech sounds convolved with such modified BRIRs. Monaural reverberation cues were found to be sufficient...

Binaural unmasking of multi-channel stimuli in bilateral cochlear implant users.

Science.gov (United States)

Van Deun, Lieselot; van Wieringen, Astrid; Francart, Tom; Büchner, Andreas; Lenarz, Thomas; Wouters, Jan

2011-10-01

Previous work suggests that bilateral cochlear implant users are sensitive to interaural cues if experimental speech processors are used to preserve accurate interaural information in the electrical stimulation pattern. Binaural unmasking occurs in adults and children when an interaural delay is applied to the envelope of a high-rate pulse train. Nevertheless, for speech perception, binaural unmasking benefits have not been demonstrated consistently, even with coordinated stimulation at both ears. The present study aimed at bridging the gap between basic psychophysical performance on binaural signal detection tasks on the one hand and binaural perception of speech in noise on the other hand. Therefore, binaural signal detection was expanded to multi-channel stimulation and biologically relevant interaural delays. A harmonic complex, consisting of three sinusoids (125, 250, and 375 Hz), was added to three 125-Hz-wide noise bands centered on the sinusoids. When an interaural delay of 700 μs was introduced, an average BMLD of 3 dB was established. Outcomes are promising in view of real-life benefits. Future research should investigate the generalization of the observed benefits for signal detection to speech perception in everyday listening situations and determine the importance of coordination of bilateral speech processors and accentuation of envelope cues.

Do hearing loss and cognitive function modulate benefit from different binaural noise-reduction settings?

Science.gov (United States)

Neher, Tobias; Grimm, Giso; Hohmann, Volker; Kollmeier, Birger

2014-01-01

Although previous research indicates that cognitive skills influence benefit from different types of hearing aid algorithms, comparatively little is known about the role of, and potential interaction with, hearing loss. This holds true especially for noise reduction (NR) processing. The purpose of the present study was thus to explore whether degree of hearing loss and cognitive function modulate benefit from different binaural NR settings based on measures of speech intelligibility, listening effort, and overall preference. Forty elderly listeners with symmetrical sensorineural hearing losses in the mild to severe range participated. They were stratified into four age-matched groups (with n = 10 per group) based on their pure-tone average hearing losses and their performance on a visual measure of working memory (WM) capacity. The algorithm under consideration was a binaural coherence-based NR scheme that suppressed reverberant signal components as well as diffuse background noise at mid to high frequencies. The strength of the applied processing was varied from inactive to strong, and testing was carried out across a range of fixed signal-to-noise ratios (SNRs). Potential benefit was assessed using a dual-task paradigm combining speech recognition with a visual reaction time (VRT) task indexing listening effort. Pairwise preference judgments were also collected. All measurements were made using headphone simulations of a frontal speech target in a busy cafeteria. Test-retest data were gathered for all outcome measures. Analysis of the test-retest data showed all data sets to be reliable. Analysis of the speech scores showed that, for all groups, speech recognition was unaffected by moderate NR processing, whereas strong NR processing reduced intelligibility by about 5%. Analysis of the VRT scores revealed a similar data pattern. That is, while moderate NR did not affect VRT performance, strong NR impaired the performance of all groups slightly. Analysis of the

Towards a binaural modelling toolbox

DEFF Research Database (Denmark)

Søndergaard, Peter Lempel; Culling, John F.; Dau, Torsten

2011-01-01

The Auditory Modelling Toolbox (AMToolbox) is a new Matlab / Octave toolbox for developing and applying auditory perceptual models and in particular binaural models. The philosophy behind the project is that the models should be implemented in a consistent manner, well documented and user...

Objective evaluation of binaural summation through acoustic reflex measures.

Science.gov (United States)

Rawool, Vishakha W; Parrill, Madaline

2018-02-12

A previous study [Rawool, V. W. (2016). Auditory processing deficits: Assessment and intervention. New York, NY: Thieme Medical Publishers, Inc., pp. 186-187] demonstrated objective assessment of binaural summation through right contralateral acoustic reflex thresholds (ARTs) in women. The current project examined if previous findings could be generalised to men and to the left ear. Cross-sectional. Sixty individuals participated in the study. Left and right contralateral ARTs were obtained in two conditions. In the alternated condition, the probe tone presentation was alternated with the presentation of the reflex activating clicks. In the simultaneous condition, the probe tone and the clicks were presented simultaneously. Binaural summation was calculated by subtracting the ARTs obtained in the simultaneous condition from the ARTs obtained in the alternated condition. MANOVA on ARTs revealed no significant gender or ear effects. The ARTs were significantly lower/better in the simultaneous condition compared to the alternated condition. Binaural summation was 4 dB or higher in 88% of the ears and 6 dB or higher in 76% of ears. Stimulation of six out of the total 120 (0.5%) ears resulted in worse thresholds in the simultaneous condition compared with the alternating condition, suggesting binaural interference.

A systematic study of binaural reproduction systems through loudspeakers

DEFF Research Database (Denmark)

Lacouture Parodi, Yesenia

This Ph.D. thesis presents an investigation of the acoustical and psycho-acoustical characteristics of binaural reproduction systems through loudspeakers. The study was mainly focused on the characteristics of closely spaced loudspeakers – known as stereo-dipoles – when placed at different...... positions, e.g. in front of, above or in the back of the head. The main objective of this study is to set foundations for the design of a binaural reproduction system that is robust to head rotations and reduces front-back confusions. Different crosstalk cancellation techniques were investigated...... when the loudspeakers are placed above the head and that closely spaced loudspeakers are more robust to lateral displacements than wider span angles. Based on the results obtained from those experiments, a binaural reproduction system that uses three stereo-dipoles is proposed: one pair in front...

Tracking EEG changes in response to alpha and beta binaural beats.

Science.gov (United States)

Vernon, D; Peryer, G; Louch, J; Shaw, M

2014-07-01

A binaural beat can be produced by presenting two tones of a differing frequency, one to each ear. Such auditory stimulation has been suggested to influence behaviour and cognition via the process of cortical entrainment. However, research so far has only shown the frequency following responses in the traditional EEG frequency ranges of delta, theta and gamma. Hence a primary aim of this research was to ascertain whether it would be possible to produce clear changes in the EEG in either the alpha or beta frequency ranges. Such changes, if possible, would have a number of important implications as well as potential applications. A secondary goal was to track any observable changes in the EEG throughout the entrainment epoch to gain some insight into the nature of the entrainment effects on any changes in an effort to identify more effective entrainment regimes. Twenty two healthy participants were recruited and randomly allocated to one of two groups, each of which was exposed to a distinct binaural beat frequency for ten 1-minute epochs. The first group listened to an alpha binaural beat of 10 Hz and the second to a beta binaural beat of 20 Hz. EEG was recorded from the left and right temporal regions during pre-exposure baselines, stimulus exposure epochs and post-exposure baselines. Analysis of changes in broad-band and narrow-band amplitudes, and frequency showed no effect of binaural beat frequency eliciting a frequency following effect in the EEG. Possible mediating factors are discussed and a number of recommendations are made regarding future studies, exploring entrainment effects from a binaural beat presentation. Copyright © 2012 Elsevier B.V. All rights reserved.

The effect of gamma-enhancing binaural beats on the control of feature bindings.

Science.gov (United States)

Colzato, Lorenza S; Steenbergen, Laura; Sellaro, Roberta

2017-07-01

Binaural beats represent the auditory experience of an oscillating sound that occurs when two sounds with neighboring frequencies are presented to one's left and right ear separately. Binaural beats have been shown to impact information processing via their putative role in increasing neural synchronization. Recent studies of feature-repetition effects demonstrated interactions between perceptual features and action-related features: repeating only some, but not all features of a perception-action episode hinders performance. These partial-repetition (or binding) costs point to the existence of temporary episodic bindings (event files) that are automatically retrieved by repeating at least one of their features. Given that neural synchronization in the gamma band has been associated with visual feature bindings, we investigated whether the impact of binaural beats extends to the top-down control of feature bindings. Healthy adults listened to gamma-frequency (40 Hz) binaural beats or to a constant tone of 340 Hz (control condition) for ten minutes before and during a feature-repetition task. While the size of visuomotor binding costs (indicating the binding of visual and action features) was unaffected by the binaural beats, the size of visual feature binding costs (which refer to the binding between the two visual features) was considerably smaller during gamma-frequency binaural beats exposure than during the control condition. Our results suggest that binaural beats enhance selectivity in updating episodic memory traces and further strengthen the hypothesis that neural activity in the gamma band is critically associated with the control of feature binding.

Application of a "relative" procedure to a problem in binaural beat perception.

Science.gov (United States)

1963-08-01

The existence of binaural beats has long been considered an indication of binaural interaction for timing and for periodicity of information. In the past, bilaterally matched sound pressure or sensation levels have been used in the investigation of t...

The disparate histories of binocular vision and binaural hearing.

Science.gov (United States)

Wade, Nicholas J

2018-01-01

Vision and hearing are dependent on disparities of spatial patterns received by two eyes and on time and intensity differences to two ears. However, the experiences of a single world have masked attention to these disparities. While eyes and ears are paired, there has not been parity in the attention directed to their functioning. Phenomena involving binocular vision were commented upon since antiquity whereas those about binaural hearing are much more recent. This history is compared with respect to the experimental manipulations of dichoptic and dichotic stimuli and the instruments used to stimulate the paired organs. Binocular color mixing led to studies of binaural hearing and direction and distance in visual localization were analyzed before those for auditory localization. Experimental investigations began in the nineteenth century with the invention of instruments like the stereoscope and pseudoscope, soon to be followed by their binaural equivalents, the stethophone and pseudophone.

Binaural release from masking with single- and multi-electrode stimulation in children with cochlear implants.

Science.gov (United States)

Todd, Ann E; Goupell, Matthew J; Litovsky, Ruth Y

2016-07-01

Cochlear implants (CIs) provide children with access to speech information from a young age. Despite bilateral cochlear implantation becoming common, use of spatial cues in free field is smaller than in normal-hearing children. Clinically fit CIs are not synchronized across the ears; thus binaural experiments must utilize research processors that can control binaural cues with precision. Research to date has used single pairs of electrodes, which is insufficient for representing speech. Little is known about how children with bilateral CIs process binaural information with multi-electrode stimulation. Toward the goal of improving binaural unmasking of speech, this study evaluated binaural unmasking with multi- and single-electrode stimulation. Results showed that performance with multi-electrode stimulation was similar to the best performance with single-electrode stimulation. This was similar to the pattern of performance shown by normal-hearing adults when presented an acoustic CI simulation. Diotic and dichotic signal detection thresholds of the children with CIs were similar to those of normal-hearing children listening to a CI simulation. The magnitude of binaural unmasking was not related to whether the children with CIs had good interaural time difference sensitivity. Results support the potential for benefits from binaural hearing and speech unmasking in children with bilateral CIs.

Binaural release from masking with single- and multi-electrode stimulation in children with cochlear implantsa)

Science.gov (United States)

Todd, Ann E.; Goupell, Matthew J.; Litovsky, Ruth Y.

2016-01-01

Cochlear implants (CIs) provide children with access to speech information from a young age. Despite bilateral cochlear implantation becoming common, use of spatial cues in free field is smaller than in normal-hearing children. Clinically fit CIs are not synchronized across the ears; thus binaural experiments must utilize research processors that can control binaural cues with precision. Research to date has used single pairs of electrodes, which is insufficient for representing speech. Little is known about how children with bilateral CIs process binaural information with multi-electrode stimulation. Toward the goal of improving binaural unmasking of speech, this study evaluated binaural unmasking with multi- and single-electrode stimulation. Results showed that performance with multi-electrode stimulation was similar to the best performance with single-electrode stimulation. This was similar to the pattern of performance shown by normal-hearing adults when presented an acoustic CI simulation. Diotic and dichotic signal detection thresholds of the children with CIs were similar to those of normal-hearing children listening to a CI simulation. The magnitude of binaural unmasking was not related to whether the children with CIs had good interaural time difference sensitivity. Results support the potential for benefits from binaural hearing and speech unmasking in children with bilateral CIs. PMID:27475132

Binaural interaction in the auditory brainstem response: a normative study.

Science.gov (United States)

Van Yper, Lindsey N; Vermeire, Katrien; De Vel, Eddy F J; Battmer, Rolf-Dieter; Dhooge, Ingeborg J M

2015-04-01

Binaural interaction can be investigated using auditory evoked potentials. A binaural interaction component can be derived from the auditory brainstem response (ABR-BIC) and is considered evidence for binaural interaction at the level of the brainstem. Although click ABR-BIC has been investigated thoroughly, data on 500 Hz tone-burst (TB) ABR-BICs are scarce. In this study, characteristics of click and 500 Hz TB ABR-BICs are described. Furthermore, reliability of both click and 500 Hz TB ABR-BIC are investigated. Eighteen normal hearing young adults (eight women, ten men) were included. ABRs were recorded in response to clicks and 500 Hz TBs. ABR-BICs were derived by subtracting the binaural response from the sum of the monaural responses measured in opposite ears. Good inter-rater reliability is obtained for both click and 500 Hz TB ABR-BICs. The most reliable peak in click ABR-BIC occurs at a mean latency of 6.06 ms (SD 0.354 ms). Reliable 500 Hz TB ABR-BIC are obtained with a mean latency of 9.47 ms (SD 0.678 ms). Amplitudes are larger for 500 Hz TB ABR-BIC than for clicks. The most reliable peak in click ABR-BIC occurs at the downslope of wave V. Five hundred Hertz TB ABR-BIC is characterized by a broad positivity occurring at the level of wave V. The ABR-BIC is a useful technique to investigate binaural interaction in certain populations. Examples are bilateral hearing aid users, bilateral cochlear implant users and bimodal listeners. The latter refers to the combination of unilateral cochlear implantation and contralateral residual hearing. The majority of these patients have residual hearing in the low frequencies. The current study suggests that 500 Hz TB ABR-BIC may be a suitable technique to assess binaural interaction in this specific population of cochlear implant users. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Cortical Correlates of Binaural Temporal Processing Deficits in Older Adults.

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Eddins, Ann Clock; Eddins, David A

This study was designed to evaluate binaural temporal processing in young and older adults using a binaural masking level difference (BMLD) paradigm. Using behavioral and electrophysiological measures within the same listeners, a series of stimulus manipulations was used to evaluate the relative contribution of binaural temporal fine-structure and temporal envelope cues. We evaluated the hypotheses that age-related declines in the BMLD task would be more strongly associated with temporal fine-structure than envelope cues and that age-related declines in behavioral measures would be correlated with cortical auditory evoked potential (CAEP) measures. Thirty adults participated in the study, including 10 young normal-hearing, 10 older normal-hearing, and 10 older hearing-impaired adults with bilaterally symmetric, mild-to-moderate sensorineural hearing loss. Behavioral and CAEP thresholds were measured for diotic (So) and dichotic (Sπ) tonal signals presented in continuous diotic (No) narrowband noise (50-Hz wide) maskers. Temporal envelope cues were manipulated by using two different narrowband maskers; Gaussian noise (GN) with robust envelope fluctuations and low-noise noise (LNN) with minimal envelope fluctuations. The potential to use temporal fine-structure cues was controlled by varying the signal frequency (500 or 4000 Hz), thereby relying on the natural decline in phase-locking with increasing frequency. Behavioral and CAEP thresholds were similar across groups for diotic conditions, while the masking release in dichotic conditions was larger for younger than for older participants. Across all participants, BMLDs were larger for GN than LNN and for 500-Hz than for 4000-Hz conditions, where envelope and fine-structure cues were most salient, respectively. Specific age-related differences were demonstrated for 500-Hz dichotic conditions in GN and LNN, reflecting reduced binaural temporal fine-structure coding. No significant age effects were observed for 4000

Contribution of Binaural Masking Release to Improved Speech Intelligibility for different Masker types.

Science.gov (United States)

Sutojo, Sarinah; van de Par, Steven; Schoenmaker, Esther

2018-06-01

In situations with competing talkers or in the presence of masking noise, speech intelligibility can be improved by spatially separating the target speaker from the interferers. This advantage is generally referred to as spatial release from masking (SRM) and different mechanisms have been suggested to explain it. One proposed mechanism to benefit from spatial cues is the binaural masking release, which is purely stimulus driven. According to this mechanism, the spatial benefit results from differences in the binaural cues of target and masker, which need to appear simultaneously in time and frequency to improve the signal detection. In an alternative proposed mechanism, the differences in the interaural cues improve the segregation of auditory streams, a process, which involves top-down processing rather than being purely stimulus driven. Other than the cues that produce binaural masking release, the interaural cue differences between target and interferer required to improve stream segregation do not have to appear simultaneously in time and frequency. This study is concerned with the contribution of binaural masking release to SRM for three masker types that differ with respect to the amount of energetic masking they exert. Speech intelligibility was measured, employing a stimulus manipulation that inhibits binaural masking release, and analyzed with a metric to account for the number of better-ear glimpses. Results indicate that the contribution of the stimulus-driven binaural masking release plays a minor role while binaural stream segregation and the availability of glimpses in the better ear had a stronger influence on improving the speech intelligibility. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

A time-domain binaural detection model and its predictions temporal-resolution data

NARCIS (Netherlands)

Breebaart, D.J.; Par, van de S.L.J.D.E.; Kohlrausch, A.G.

2002-01-01

This paper discusses the application of a time-domain binaural signal-detection model in the context of estimates of the temporal resolution of the binaural auditory system. It is demonstrated that the optimal detector which is present in the model is crucial to account for specific temporal

Calibration aspects of binaural sound reproduction over insert earphones

DEFF Research Database (Denmark)

Hoffmann, Pablo F.; Markovic, Milos; Olesen, Søren Krarup

2012-01-01

Earphones are nowadays widely adopted for the reproduction of audio material in mobile multimedia and communication platforms, e.g. smartphones. Reproduction of high-quality spatial sound on such platforms can dramatically improve their applicability, and since two channels are always available...... in earphone-based reproduction, binaural reproduction can be applied directly. This paper is concerned with the theoretical and practical aspects relevant to the correct reproduction of binaural signals over insert earphones. To this purpose, a theoretical model originally developed to explain the acoustic...

Efficiency of brainwave entrainment by binaural beats in reducing anxiety

Directory of Open Access Journals (Sweden)

Ahmad Alipoor

2014-04-01

Full Text Available Background: Anxiety is a fundamental phenomenon that is a common symptom in all mental disorders. The aim of the present study was to assess the effect of brainwave entrainment on anxiety reduction using binaural beats. Methods: In this experimental double-blind study, 30 employees were selected from an engineering research firm through random sampling and replacement and divided into two groups: control group and experimental group. All participants completed the Spielberger’s State-Trait Anxiety Inventory (STAI. Then, the experimental group listened to binaural beats which was recorded on a non-vocal piece of music for 4 weeks, 3 sessions each week. Each session lasted about 20 minutes. At the same time, the control group listened to the background music without any entrainment sound. At the end, both groups completed the anxiety questionnaire and the anxiety scores of both groups obtained before and after intervention were analyzed by ANCOVA. Results: The findings showed that the brainwave entrainment using binaural beats led to the significant reduction of state anxiety (P<0.001 and trait anxiety (P<0.018. Conclusion: Brainwave entrainment using binaural beats is an effective factor in decreasing state and trait anxiety; so, it can be used to reduce anxiety in mental health centers.

Advantages of binaural amplification to acceptable noise level of directional hearing aid users.

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Kim, Ja-Hee; Lee, Jae Hee; Lee, Ho-Ki

2014-06-01

The goal of the present study was to examine whether Acceptable Noise Levels (ANLs) would be lower (greater acceptance of noise) in binaural listening than in monaural listening condition and also whether meaningfulness of background speech noise would affect ANLs for directional microphone hearing aid users. In addition, any relationships between the individual binaural benefits on ANLs and the individuals' demographic information were investigated. Fourteen hearing aid users (mean age, 64 years) participated for experimental testing. For the ANL calculation, listeners' most comfortable listening levels and background noise level were measured. Using Korean ANL material, ANLs of all participants were evaluated under monaural and binaural amplification with a counterbalanced order. The ANLs were also compared across five types of competing speech noises, consisting of 1- through 8-talker background speech maskers. Seven young normal-hearing listeners (mean age, 27 years) participated for the same measurements as a pilot testing. The results demonstrated that directional hearing aid users accepted more noise (lower ANLs) with binaural amplification than with monaural amplification, regardless of the type of competing speech. When the background speech noise became more meaningful, hearing-impaired listeners accepted less amount of noise (higher ANLs), revealing that ANL is dependent on the intelligibility of the competing speech. The individuals' binaural advantages in ANLs were significantly greater for the listeners with longer experience of hearing aids, yet not related to their age or hearing thresholds. Binaural directional microphone processing allowed hearing aid users to accept a greater amount of background noise, which may in turn improve listeners' hearing aid success. Informational masking substantially influenced background noise acceptance. Given a significant association between ANLs and duration of hearing aid usage, ANL measurement can be useful for

Electrophysiological measurement of binaural beats: effects of primary tone frequency and observer age.

Science.gov (United States)

Grose, John H; Mamo, Sara K

2012-01-01

The purpose of this study was to determine the reliability of the electrophysiological binaural beat steady state response as a gauge of temporal fine structure coding, particularly as it relates to the aging auditory system. The hypothesis was that the response would be more robust in a lower, than in a higher, frequency region and in younger, than in older, adults. Two experiments were undertaken. The first measured the 40 Hz binaural beat steady state response elicited by tone pairs in two frequency regions: lower (390 and 430 Hz tone pair) and higher (810 and 850 Hz tone pair). Frequency following responses (FFRs) evoked by the tones were also recorded. Ten young adults with normal hearing participated. The second experiment measured the binaural beat and FFRs in older adults but only in the lower frequency region. Fourteen older adults with relatively normal hearing participated. Response metrics in both experiments included response component signal-to-noise ratio (F statistic) and magnitude-squared coherence. Experiment 1 showed that FFRs were elicited in both frequency regions but were more robust in the lower frequency region. Binaural beat responses elicited by the lower frequency pair of tones showed greater amplitude fluctuation within a participant than the respective FFRs. Experiment 2 showed that older adults exhibited similar FFRs to younger adults, but proportionally fewer older participants showed binaural beat responses. Age differences in onset responses were also observed. The lower prevalence of the binaural beat response in older adults, despite the presence of FFRs, provides tentative support for the sensitivity of this measure to age-related deficits in temporal processing. However, the lability of the binaural beat response advocates caution in its use as an objective measure of fine structure coding.

Advancing Binaural Cochlear Implant Technology

Directory of Open Access Journals (Sweden)

Mathias Dietz

2015-12-01

Full Text Available This special issue contains a collection of 13 papers highlighting the collaborative research and engineering project entitled Advancing Binaural Cochlear Implant Technology—ABCIT—as well as research spin-offs from the project. In this introductory editorial, a brief history of the project is provided, alongside an overview of the studies.

La música binaural en el aprendizaje de los estudiantes universitarios. Lima 2015

OpenAIRE

Doria Palomino, Gian Carlo

2015-01-01

En este estudio titulado “La música binaural en el aprendizaje de los estudiantes universitarios Lima 2015”, tiene como objetivo demostrar que la música binaural puede mejorar el aprendizaje en los estudiantes del quinto ciclo de la carrera de administración de la Universidad Tecnológica del Perú. Esto como respuesta al problema: ¿En qué medida la estimulación de ondas cerebrales con música binaural" mejora el aprendizaje de los alumnos del quinto ciclo de la carrera de admi...

Model based Binaural Enhancement of Voiced and Unvoiced Speech

DEFF Research Database (Denmark)

Kavalekalam, Mathew Shaji; Christensen, Mads Græsbøll; Boldt, Jesper B.

2017-01-01

This paper deals with the enhancement of speech in presence of non-stationary babble noise. A binaural speech enhancement framework is proposed which takes into account both the voiced and unvoiced speech production model. The usage of this model in enhancement requires the Short term predictor...... (STP) parameters and the pitch information to be estimated. This paper uses a codebook based approach for estimating the STP parameters and a parametric binaural method is proposed for estimating the pitch parameters. Improvements in objective score are shown when using the voicedunvoiced speech model...

Binaural Perception in Young Infants.

Science.gov (United States)

Bundy, Robert S.

This paper describes three experiments which demonstrated the presence of binaural perception abilities (the ability to use both ears) in 4-month-old but not in 2-month-old infants. All of the experiments employed a visual fixation habituation-dishabituation paradigm in which infants were given a series of visual fixation trials while binaural…

A Binaural Grouping Model for Predicting Speech Intelligibility in Multitalker Environments

Directory of Open Access Journals (Sweden)

Jing Mi

2016-09-01

Full Text Available Spatially separating speech maskers from target speech often leads to a large intelligibility improvement. Modeling this phenomenon has long been of interest to binaural-hearing researchers for uncovering brain mechanisms and for improving signal-processing algorithms in hearing-assistive devices. Much of the previous binaural modeling work focused on the unmasking enabled by binaural cues at the periphery, and little quantitative modeling has been directed toward the grouping or source-separation benefits of binaural processing. In this article, we propose a binaural model that focuses on grouping, specifically on the selection of time-frequency units that are dominated by signals from the direction of the target. The proposed model uses Equalization-Cancellation (EC processing with a binary decision rule to estimate a time-frequency binary mask. EC processing is carried out to cancel the target signal and the energy change between the EC input and output is used as a feature that reflects target dominance in each time-frequency unit. The processing in the proposed model requires little computational resources and is straightforward to implement. In combination with the Coherence-based Speech Intelligibility Index, the model is applied to predict the speech intelligibility data measured by Marrone et al. The predicted speech reception threshold matches the pattern of the measured data well, even though the predicted intelligibility improvements relative to the colocated condition are larger than some of the measured data, which may reflect the lack of internal noise in this initial version of the model.

A Binaural Grouping Model for Predicting Speech Intelligibility in Multitalker Environments.

Science.gov (United States)

Mi, Jing; Colburn, H Steven

2016-10-03

Spatially separating speech maskers from target speech often leads to a large intelligibility improvement. Modeling this phenomenon has long been of interest to binaural-hearing researchers for uncovering brain mechanisms and for improving signal-processing algorithms in hearing-assistive devices. Much of the previous binaural modeling work focused on the unmasking enabled by binaural cues at the periphery, and little quantitative modeling has been directed toward the grouping or source-separation benefits of binaural processing. In this article, we propose a binaural model that focuses on grouping, specifically on the selection of time-frequency units that are dominated by signals from the direction of the target. The proposed model uses Equalization-Cancellation (EC) processing with a binary decision rule to estimate a time-frequency binary mask. EC processing is carried out to cancel the target signal and the energy change between the EC input and output is used as a feature that reflects target dominance in each time-frequency unit. The processing in the proposed model requires little computational resources and is straightforward to implement. In combination with the Coherence-based Speech Intelligibility Index, the model is applied to predict the speech intelligibility data measured by Marrone et al. The predicted speech reception threshold matches the pattern of the measured data well, even though the predicted intelligibility improvements relative to the colocated condition are larger than some of the measured data, which may reflect the lack of internal noise in this initial version of the model. © The Author(s) 2016.

Transformation of binaural response properties in the ascending auditory pathway: influence of time-varying interaural phase disparity.

Science.gov (United States)

Spitzer, M W; Semple, M N

1998-12-01

Transformation of binaural response properties in the ascending auditory pathway: influence of time-varying interaural phase disparity. J. Neurophysiol. 80: 3062-3076, 1998. Previous studies demonstrated that tuning of inferior colliculus (IC) neurons to interaural phase disparity (IPD) is often profoundly influenced by temporal variation of IPD, which simulates the binaural cue produced by a moving sound source. To determine whether sensitivity to simulated motion arises in IC or at an earlier stage of binaural processing we compared responses in IC with those of two major IPD-sensitive neuronal classes in the superior olivary complex (SOC), neurons whose discharges were phase locked (PL) to tonal stimuli and those that were nonphase locked (NPL). Time-varying IPD stimuli consisted of binaural beats, generated by presenting tones of slightly different frequencies to the two ears, and interaural phase modulation (IPM), generated by presenting a pure tone to one ear and a phase modulated tone to the other. IC neurons and NPL-SOC neurons were more sharply tuned to time-varying than to static IPD, whereas PL-SOC neurons were essentially uninfluenced by the mode of stimulus presentation. Preferred IPD was generally similar in responses to static and time-varying IPD for all unit populations. A few IC neurons were highly influenced by the direction and rate of simulated motion, but the major effect for most IC neurons and all SOC neurons was a linear shift of preferred IPD at high rates-attributable to response latency. Most IC and NPL-SOC neurons were strongly influenced by IPM stimuli simulating motion through restricted ranges of azimuth; simulated motion through partially overlapping azimuthal ranges elicited discharge profiles that were highly discontiguous, indicating that the response associated with a particular IPD is dependent on preceding portions of the stimulus. In contrast, PL-SOC responses tracked instantaneous IPD throughout the trajectory of simulated

Directional resolution of head-related transfer functions required in binaural synthesis

DEFF Research Database (Denmark)

Minnaar, Pauli; Plogsties, Jan; Christensen, Flemming

2005-01-01

In binaural synthesis a virtual sound source is implemented by convolving an anechoic signal with a pair of head-related transfer functions (HRTFs). In order to represent all possible directions of the sound source with respect to the listener a discrete number of HRTFs are measured and interpola......In binaural synthesis a virtual sound source is implemented by convolving an anechoic signal with a pair of head-related transfer functions (HRTFs). In order to represent all possible directions of the sound source with respect to the listener a discrete number of HRTFs are measured...... and moving sound sources. A criterion was found that predicts the experimental results. This criterion was used to estimate the directional resolution required in binaural synthesis for all directions on the sphere around the head....

Spectral integration in binaural signal detection

NARCIS (Netherlands)

Breebaart, D.J.; Par, van de S.L.J.D.E.; Kohlrausch, A.G.

1997-01-01

For both monaural and binaural masking, the spectral content of the masker and of the signal to be detected are important stimulus properties influencing the detection process. It is generally accepted that the auditory system separates the incoming signals in several frequency bands. It is not

Setup for demonstrating interactive binaural synthesis for telepresence applications

DEFF Research Database (Denmark)

Madsen, Esben; Olesen, Søren Krarup; Markovic, Milos

2011-01-01

position Totem with a single loudspeaker. The Position and movements of participants, particularly the head, are tracked and from this sound is rendered to include binaural cues so the Visitor is able to move around in a limited space while perceiving Destination sound as "stationary". This setup includes......, latency and transmission reliablity must be adjusted to obtain the best compromise. Bandwidth use and reliablity can be improved at the cost of latency. Finally the binaural synthesis for each source is processed at the listener's site (here Visitor) to have a minimum latency on responding to movement...

Effect of direction on loudness in individual binaural synthesis

DEFF Research Database (Denmark)

Sivonen, Ville Pekka; Minnaar, Pauli; Ellermeier, Wolfgang

2005-01-01

The effect of sound incidence angle on loudness is investigated in this study using binaural synthesis. Individual head-related transfer functions (HRTFs) and headphone equalization are used to present narrow-band noises from different directions to listeners. Their task is to match the loudness...... of these stimuli in an adaptive procedure to a reference noise in front of the listeners. The results are compared to an earlier investigation with the same experimental design in a real sound field. Based on the results the role of the individual HRTFs in loudness judgments is inspected, and finally, binaural...

The effect of cochlear nonlinearities on binaural masking level differences

DEFF Research Database (Denmark)

Le Goff, Nicolas; Kohlrausch, Armin

Background The binaural masking level difference (BMLD) has been shown to be constant (10−15dB) for masker spectrum levels from 70dB/Hz down to 30−40dB/Hz and to gradually decrease with lower levels (McFadden, 1968; Hall and Harvey, 1984). The decrease at low levels was larger in an asymmetric...... on the BMLD was investigated using an equalization−cancelation (EC) based binaural model framework. Methods The BMLD was measured for 500−Hz target tones presented in 3−kHz−wide maskers. BMLDs were obtained as a function of masker level in one symmetric and two asymmetric masker conditions: (i) No...... of 20dB/Hz in the non−attenuated ear. An EC based binaural model with a frontend including nonlinear peripheral processing (Jepsen et al., 2011) was used to predict these results. Results The BMLD obtained in the No′Sπ′50 condition was smaller than that obtained in the NoSπ condition at all masker...

Exploiting Deep Neural Networks and Head Movements for Robust Binaural Localization of Multiple Sources in Reverberant Environments

DEFF Research Database (Denmark)

Ma, Ning; May, Tobias; Brown, Guy J.

2017-01-01

This paper presents a novel machine-hearing system that exploits deep neural networks (DNNs) and head movements for robust binaural localization of multiple sources in reverberant environments. DNNs are used to learn the relationship between the source azimuth and binaural cues, consisting...... of the complete cross-correlation function (CCF) and interaural level differences (ILDs). In contrast to many previous binaural hearing systems, the proposed approach is not restricted to localization of sound sources in the frontal hemifield. Due to the similarity of binaural cues in the frontal and rear...

Contribution of low- and high-frequency bands to binaural unmasking in hearing-impaired listeners

DEFF Research Database (Denmark)

Locsei, Gusztav; Dau, Torsten; Santurette, Sébastien

2017-01-01

This study investigated the contribution of interaural timing differences (ITDs) in different frequency regions to binaural unmasking (BU) of speech. Speech reception thresholds (SRTs) and binaural intelligibility level differences (BILDs) were measured in two-talker babble in 6 young normal-hear...

Comparing Binaural Pre-processing Strategies II: Speech Intelligibility of Bilateral Cochlear Implant Users.

Science.gov (United States)

Baumgärtel, Regina M; Hu, Hongmei; Krawczyk-Becker, Martin; Marquardt, Daniel; Herzke, Tobias; Coleman, Graham; Adiloğlu, Kamil; Bomke, Katrin; Plotz, Karsten; Gerkmann, Timo; Doclo, Simon; Kollmeier, Birger; Hohmann, Volker; Dietz, Mathias

2015-12-30

Several binaural audio signal enhancement algorithms were evaluated with respect to their potential to improve speech intelligibility in noise for users of bilateral cochlear implants (CIs). 50% speech reception thresholds (SRT50) were assessed using an adaptive procedure in three distinct, realistic noise scenarios. All scenarios were highly nonstationary, complex, and included a significant amount of reverberation. Other aspects, such as the perfectly frontal target position, were idealized laboratory settings, allowing the algorithms to perform better than in corresponding real-world conditions. Eight bilaterally implanted CI users, wearing devices from three manufacturers, participated in the study. In all noise conditions, a substantial improvement in SRT50 compared to the unprocessed signal was observed for most of the algorithms tested, with the largest improvements generally provided by binaural minimum variance distortionless response (MVDR) beamforming algorithms. The largest overall improvement in speech intelligibility was achieved by an adaptive binaural MVDR in a spatially separated, single competing talker noise scenario. A no-pre-processing condition and adaptive differential microphones without a binaural link served as the two baseline conditions. SRT50 improvements provided by the binaural MVDR beamformers surpassed the performance of the adaptive differential microphones in most cases. Speech intelligibility improvements predicted by instrumental measures were shown to account for some but not all aspects of the perceptually obtained SRT50 improvements measured in bilaterally implanted CI users. © The Author(s) 2015.

Binaural fusion and listening effort in children who use bilateral cochlear implants: a psychoacoustic and pupillometric study.

Science.gov (United States)

Steel, Morrison M; Papsin, Blake C; Gordon, Karen A

2015-01-01

Bilateral cochlear implants aim to provide hearing to both ears for children who are deaf and promote binaural/spatial hearing. Benefits are limited by mismatched devices and unilaterally-driven development which could compromise the normal integration of left and right ear input. We thus asked whether children hear a fused image (ie. 1 vs 2 sounds) from their bilateral implants and if this "binaural fusion" reduces listening effort. Binaural fusion was assessed by asking 25 deaf children with cochlear implants and 24 peers with normal hearing whether they heard one or two sounds when listening to bilaterally presented acoustic click-trains/electric pulses (250 Hz trains of 36 ms presented at 1 Hz). Reaction times and pupillary changes were recorded simultaneously to measure listening effort. Bilaterally implanted children heard one image of bilateral input less frequently than normal hearing peers, particularly when intensity levels on each side were balanced. Binaural fusion declined as brainstem asymmetries increased and age at implantation decreased. Children implanted later had access to acoustic input prior to implantation due to progressive deterioration of hearing. Increases in both pupil diameter and reaction time occurred as perception of binaural fusion decreased. Results indicate that, without binaural level cues, children have difficulty fusing input from their bilateral implants to perceive one sound which costs them increased listening effort. Brainstem asymmetries exacerbate this issue. By contrast, later implantation, reflecting longer access to bilateral acoustic hearing, may have supported development of auditory pathways underlying binaural fusion. Improved integration of bilateral cochlear implant signals for children is required to improve their binaural hearing.

A machine-hearing system exploiting head movements for binaural sound localisation in reverberant conditions

DEFF Research Database (Denmark)

May, Tobias; Ma, Ning; Wierstorf, Hagen

2015-01-01

This paper is concerned with machine localisation of multiple active speech sources in reverberant environments using two (binaural) microphones. Such conditions typically present a problem for ‘classical’ binaural models. Inspired by the human ability to utilise head movements, the current study...

Lateralization and Binaural Interaction of Middle-Latency and Late-Brainstem Components of the Auditory Evoked Response.

Science.gov (United States)

Dykstra, Andrew R; Burchard, Daniel; Starzynski, Christian; Riedel, Helmut; Rupp, Andre; Gutschalk, Alexander

2016-08-01

We used magnetoencephalography to examine lateralization and binaural interaction of the middle-latency and late-brainstem components of the auditory evoked response (the MLR and SN10, respectively). Click stimuli were presented either monaurally, or binaurally with left- or right-leading interaural time differences (ITDs). While early MLR components, including the N19 and P30, were larger for monaural stimuli presented contralaterally (by approximately 30 and 36 % in the left and right hemispheres, respectively), later components, including the N40 and P50, were larger ipsilaterally. In contrast, MLRs elicited by binaural clicks with left- or right-leading ITDs did not differ. Depending on filter settings, weak binaural interaction could be observed as early as the P13 but was clearly much larger for later components, beginning at the P30, indicating some degree of binaural linearity up to early stages of cortical processing. The SN10, an obscure late-brainstem component, was observed consistently in individuals and showed linear binaural additivity. The results indicate that while the MLR is lateralized in response to monaural stimuli-and not ITDs-this lateralization reverses from primarily contralateral to primarily ipsilateral as early as 40 ms post stimulus and is never as large as that seen with fMRI.

Binaural fusion and the representation of virtual pitch in the human auditory cortex.

Science.gov (United States)

Pantev, C; Elbert, T; Ross, B; Eulitz, C; Terhardt, E

1996-10-01

The auditory system derives the pitch of complex tones from the tone's harmonics. Research in psychoacoustics predicted that binaural fusion was an important feature of pitch processing. Based on neuromagnetic human data, the first neurophysiological confirmation of binaural fusion in hearing is presented. The centre of activation within the cortical tonotopic map corresponds to the location of the perceived pitch and not to the locations that are activated when the single frequency constituents are presented. This is also true when the different harmonics of a complex tone are presented dichotically. We conclude that the pitch processor includes binaural fusion to determine the particular pitch location which is activated in the auditory cortex.

Eliminating the Attentional Blink through Binaural Beats: A Case for Tailored Cognitive Enhancement.

Science.gov (United States)

Reedijk, Susan A; Bolders, Anne; Colzato, Lorenza S; Hommel, Bernhard

2015-01-01

Enhancing human cognitive performance is a topic that continues to spark scientific interest. Studies into cognitive-enhancement techniques often fail to take inter-individual differences into account, however, which leads to underestimation of the effectiveness of these techniques. The current study investigated the effect of binaural beats, a cognitive-enhancement technique, on attentional control in an attentional blink (AB) task. As predicted from a neurocognitive approach to cognitive control, high-frequency binaural beats eliminated the AB, but only in individuals with low spontaneous eye-blink rates (indicating low striatal dopamine levels). This suggests that the way in which cognitive-enhancement techniques, such as binaural beats, affect cognitive performance depends on inter-individual differences.

Eliminating the attentional blink through binaural beats: A case for tailored cognitive enhancement

Directory of Open Access Journals (Sweden)

Susan A. Reedijk

2015-06-01

Full Text Available Enhancing human cognitive performance is a topic that continues to spark scientific interest. Studies into cognitive enhancement techniques often fail to take inter-individual differences into account, however, which leads to underestimation of the effectiveness of these techniques. The current study investigated the effect of binaural beats, a cognitive enhancement technique, on attentional control in an attentional blink task. As predicted from a neurocognitive approach to cognitive control, high-frequency binaural beats eliminated the attentional blink, but only in individuals with low spontaneous eye-blink rates (indicating low striatal dopamine levels. This suggests that the way in which cognitive enhancement techniques, such as binaural beats, affect cognitive performance depends on inter-individual differences.

Binaural Fusion and Listening Effort in Children Who Use Bilateral Cochlear Implants: A Psychoacoustic and Pupillometric Study

Science.gov (United States)

Steel, Morrison M.; Papsin, Blake C.; Gordon, Karen A.

2015-01-01

Bilateral cochlear implants aim to provide hearing to both ears for children who are deaf and promote binaural/spatial hearing. Benefits are limited by mismatched devices and unilaterally-driven development which could compromise the normal integration of left and right ear input. We thus asked whether children hear a fused image (ie. 1 vs 2 sounds) from their bilateral implants and if this “binaural fusion” reduces listening effort. Binaural fusion was assessed by asking 25 deaf children with cochlear implants and 24 peers with normal hearing whether they heard one or two sounds when listening to bilaterally presented acoustic click-trains/electric pulses (250 Hz trains of 36 ms presented at 1 Hz). Reaction times and pupillary changes were recorded simultaneously to measure listening effort. Bilaterally implanted children heard one image of bilateral input less frequently than normal hearing peers, particularly when intensity levels on each side were balanced. Binaural fusion declined as brainstem asymmetries increased and age at implantation decreased. Children implanted later had access to acoustic input prior to implantation due to progressive deterioration of hearing. Increases in both pupil diameter and reaction time occurred as perception of binaural fusion decreased. Results indicate that, without binaural level cues, children have difficulty fusing input from their bilateral implants to perceive one sound which costs them increased listening effort. Brainstem asymmetries exacerbate this issue. By contrast, later implantation, reflecting longer access to bilateral acoustic hearing, may have supported development of auditory pathways underlying binaural fusion. Improved integration of bilateral cochlear implant signals for children is required to improve their binaural hearing. PMID:25668423

Binaural fusion and listening effort in children who use bilateral cochlear implants: a psychoacoustic and pupillometric study.

Directory of Open Access Journals (Sweden)

Morrison M Steel

Full Text Available Bilateral cochlear implants aim to provide hearing to both ears for children who are deaf and promote binaural/spatial hearing. Benefits are limited by mismatched devices and unilaterally-driven development which could compromise the normal integration of left and right ear input. We thus asked whether children hear a fused image (ie. 1 vs 2 sounds from their bilateral implants and if this "binaural fusion" reduces listening effort. Binaural fusion was assessed by asking 25 deaf children with cochlear implants and 24 peers with normal hearing whether they heard one or two sounds when listening to bilaterally presented acoustic click-trains/electric pulses (250 Hz trains of 36 ms presented at 1 Hz. Reaction times and pupillary changes were recorded simultaneously to measure listening effort. Bilaterally implanted children heard one image of bilateral input less frequently than normal hearing peers, particularly when intensity levels on each side were balanced. Binaural fusion declined as brainstem asymmetries increased and age at implantation decreased. Children implanted later had access to acoustic input prior to implantation due to progressive deterioration of hearing. Increases in both pupil diameter and reaction time occurred as perception of binaural fusion decreased. Results indicate that, without binaural level cues, children have difficulty fusing input from their bilateral implants to perceive one sound which costs them increased listening effort. Brainstem asymmetries exacerbate this issue. By contrast, later implantation, reflecting longer access to bilateral acoustic hearing, may have supported development of auditory pathways underlying binaural fusion. Improved integration of bilateral cochlear implant signals for children is required to improve their binaural hearing.

Improvements in Speech Understanding With Wireless Binaural Broadband Digital Hearing Instruments in Adults With Sensorineural Hearing Loss

OpenAIRE

Kreisman, Brian M.; Mazevski, Annette G.; Schum, Donald J.; Sockalingam, Ravichandran

2010-01-01

This investigation examined whether speech intelligibility in noise can be improved using a new, binaural broadband hearing instrument system. Participants were 36 adults with symmetrical, sensorineural hearing loss (18 experienced hearing instrument users and 18 without prior experience). Participants were fit binaurally in a planned comparison, randomized crossover design study with binaural broadband hearing instruments and advanced digital hearing instruments. Following an adjustment peri...

Emphasis of spatial cues in the temporal fine structure during the rising segments of amplitude-modulated sounds

Science.gov (United States)

Dietz, Mathias; Marquardt, Torsten; Salminen, Nelli H.; McAlpine, David

2013-01-01

The ability to locate the direction of a target sound in a background of competing sources is critical to the survival of many species and important for human communication. Nevertheless, brain mechanisms that provide for such accurate localization abilities remain poorly understood. In particular, it remains unclear how the auditory brain is able to extract reliable spatial information directly from the source when competing sounds and reflections dominate all but the earliest moments of the sound wave reaching each ear. We developed a stimulus mimicking the mutual relationship of sound amplitude and binaural cues, characteristic to reverberant speech. This stimulus, named amplitude modulated binaural beat, allows for a parametric and isolated change of modulation frequency and phase relations. Employing magnetoencephalography and psychoacoustics it is demonstrated that the auditory brain uses binaural information in the stimulus fine structure only during the rising portion of each modulation cycle, rendering spatial information recoverable in an otherwise unlocalizable sound. The data suggest that amplitude modulation provides a means of “glimpsing” low-frequency spatial cues in a manner that benefits listening in noisy or reverberant environments. PMID:23980161

A new approach to comparing binaural masking level differences at low and high frequencies

NARCIS (Netherlands)

Par, van de S.L.J.D.E.; Kohlrausch, A.G.

1997-01-01

A new experimental technique for studying binaural processing at high frequencies is introduced. Binaural masking level differences (BMLDs) for the conditions N0S and NS0 were measured for a tonal signal in narrow-band noise at 125, 250, and 4000 Hz. In addition, "transposed" stimuli were generated,

Binaural loudness for artificial-head measurements in directional sound fields

DEFF Research Database (Denmark)

Sivonen, Ville Pekka; Ellermeier, Wolfgang

2008-01-01

The effect of the sound incidence angle on loudness was investigated for fifteen listeners who matched the loudness of sounds coming from five different incidence angles in the horizontal plane to that of the same sound with frontal incidence. The stimuli were presented via binaural synthesis...... by using head-related transfer functions measured for an artificial head. The results, which exhibited marked individual differences, show that loudness depends on the direction from which a sound reaches the listener. The average results suggest a relatively simple rule for combining the two signals...... at the ears of an artificial head for binaural loudness predictions....

High-Frequency Binaural Beats Increase Cognitive Flexibility: Evidence from Dual-Task Crosstalk.

Science.gov (United States)

Hommel, Bernhard; Sellaro, Roberta; Fischer, Rico; Borg, Saskia; Colzato, Lorenza S

2016-01-01

Increasing evidence suggests that cognitive-control processes can be configured to optimize either persistence of information processing (by amplifying competition between decision-making alternatives and top-down biasing of this competition) or flexibility (by dampening competition and biasing). We investigated whether high-frequency binaural beats, an auditory illusion suspected to act as a cognitive enhancer, have an impact on cognitive-control configuration. We hypothesized that binaural beats in the gamma range bias the cognitive-control style toward flexibility, which in turn should increase the crosstalk between tasks in a dual-task paradigm. We replicated earlier findings that the reaction time in the first-performed task is sensitive to the compatibility between the responses in the first and the second task-an indication of crosstalk. As predicted, exposing participants to binaural beats in the gamma range increased this effect as compared to a control condition in which participants were exposed to a continuous tone of 340 Hz. These findings provide converging evidence that the cognitive-control style can be systematically biased by inducing particular internal states; that high-frequency binaural beats bias the control style toward more flexibility; and that different styles are implemented by changing the strength of local competition and top-down bias.

High-frequency binaural beats increase cognitive flexibility: evidence from dual-task crosstalk

Directory of Open Access Journals (Sweden)

Bernhard Hommel

2016-08-01

Full Text Available Increasing evidence suggests that cognitive-control processes can be configured to optimize either persistence of information processing (by amplifying competition between decision-making alternatives and top-down biasing of this competition or flexibility (by dampening competition and biasing. We investigated whether high-frequency binaural beats, an auditory illusion suspected to act as a cognitive enhancer, have an impact on cognitive-control configuration. We hypothesized that binaural beats in the gamma range bias the cognitive-control style towards flexibility, which in turn should increase the crosstalk between tasks in a dual-task paradigm. We replicated earlier findings that the reaction time in the first-performed task is sensitive to the compatibility between the responses in the first and the second task—an indication of crosstalk. As predicted, exposing participants to binaural beats in the gamma range increased this effect as compared to a control condition in which participants were exposed to a continuous tone of 340 Hz. These findings provide converging evidence that the cognitive-control style can be systematically biased by inducing particular internal states; that high-frequency binaural beats bias the control style towards more flexibility; and that different styles are implemented by changing the strength of local competition and top-down bias.

A New Perspective on Binaural Integration Using Response Time Methodology: Super Capacity Revealed in Conditions of Binaural Masking Release

Directory of Open Access Journals (Sweden)

Jennifer eLentz

2014-08-01

Full Text Available This study applied reaction-time based methods to assess the workload capacity of binaural integration by comparing reaction time distributions for monaural and binaural tone-in-noise detection tasks. In the diotic contexts, an identical tone + noise stimulus was presented to each ear. In the dichotic contexts, an identical noise was presented to each ear, but the tone was presented to one of the ears 180o out of phase with respect to the other ear. Accuracy-based measurements have demonstrated a much lower signal detection threshold for the dichotic versus the diotic conditions, but accuracy-based techniques do not allow for assessment of system dynamics or resource allocation across time. Further, reaction times allow comparisons between these conditions at the same signal-to-noise ratio. Here, we apply a reaction-time based capacity coefficient, which provides an index of workload efficiency and quantifies the resource allocations for single ear versus two ear presentations. We demonstrate that the release from masking generated by the addition of an identical stimulus to one ear is limited-to-unlimited capacity (efficiency typically less than 1, consistent with less gain than would be expected by probability summation. However, the dichotic presentation leads to a significant increase in workload capacity (increased efficiency – most specifically at lower signal-to-noise ratios. These experimental results provide further evidence that configural processing plays a critical role in binaural masking release, and that these mechanisms may operate more strongly when the signal stimulus is difficult to detect, albeit still with nearly 100% accuracy.

A new perspective on binaural integration using response time methodology: super capacity revealed in conditions of binaural masking release.

Science.gov (United States)

Lentz, Jennifer J; He, Yuan; Townsend, James T

2014-01-01

This study applied reaction-time based methods to assess the workload capacity of binaural integration by comparing reaction time (RT) distributions for monaural and binaural tone-in-noise detection tasks. In the diotic contexts, an identical tone + noise stimulus was presented to each ear. In the dichotic contexts, an identical noise was presented to each ear, but the tone was presented to one of the ears 180° out of phase with respect to the other ear. Accuracy-based measurements have demonstrated a much lower signal detection threshold for the dichotic vs. the diotic conditions, but accuracy-based techniques do not allow for assessment of system dynamics or resource allocation across time. Further, RTs allow comparisons between these conditions at the same signal-to-noise ratio. Here, we apply a reaction-time based capacity coefficient, which provides an index of workload efficiency and quantifies the resource allocations for single ear vs. two ear presentations. We demonstrate that the release from masking generated by the addition of an identical stimulus to one ear is limited-to-unlimited capacity (efficiency typically less than 1), consistent with less gain than would be expected by probability summation. However, the dichotic presentation leads to a significant increase in workload capacity (increased efficiency)-most specifically at lower signal-to-noise ratios. These experimental results provide further evidence that configural processing plays a critical role in binaural masking release, and that these mechanisms may operate more strongly when the signal stimulus is difficult to detect, albeit still with nearly 100% accuracy.

Improvements in speech understanding with wireless binaural broadband digital hearing instruments in adults with sensorineural hearing loss.

Science.gov (United States)

Kreisman, Brian M; Mazevski, Annette G; Schum, Donald J; Sockalingam, Ravichandran

2010-03-01

This investigation examined whether speech intelligibility in noise can be improved using a new, binaural broadband hearing instrument system. Participants were 36 adults with symmetrical, sensorineural hearing loss (18 experienced hearing instrument users and 18 without prior experience). Participants were fit binaurally in a planned comparison, randomized crossover design study with binaural broadband hearing instruments and advanced digital hearing instruments. Following an adjustment period with each device, participants underwent two speech-in-noise tests: the QuickSIN and the Hearing in Noise Test (HINT). Results suggested significantly better performance on the QuickSIN and the HINT measures with the binaural broadband hearing instruments, when compared with the advanced digital hearing instruments and unaided, across and within all noise conditions.

Binaural beat technology in humans: a pilot study to assess psychologic and physiologic effects.

Science.gov (United States)

Wahbeh, Helané; Calabrese, Carlo; Zwickey, Heather

2007-01-01

Binaural beat technology (BBT) products are sold internationally as personal development and health improvement tools. Producers suggest benefit from regular listening to binaural beats including reduced stress and anxiety, and increased focus, concentration, motivation, confidence, and depth in meditation. Binaural beats are auditory brainstem responses that originate in the superior olivary nucleus as a result of different frequency auditory stimuli provided to each ear. Listeners to binaural beat "hear" a beat at a frequency equal to the difference between the frequencies of the applied tones. The objectives of this pilot study were to gather preliminary data on psychologic and physiologic effects of 60 days daily use of BBT for hypothesis generation and to assess compliance, feasibility, and safety for future studies. Uncontrolled pilot study. Eight healthy adults participated in the study. Participants listened to a CD with delta (0-4 Hz) binaural beat frequencies daily for 60 days. Psychologic and physiological data were collected before and after a 60-day intervention. PSYCHOLOGIC: Depression (Beck Depression Inventory-2), anxiety (State-Trait Anxiety Inventory), mood (Profile of Mood States), absorption (Tellegen Absorption Scale) and quality of Life (World Health Organization-Quality of Life Inventory). PHYSIOLOGICAL: Cortisol, dehydroepiandrosterone, melatonin, insulin-like growth factor-1, serotonin, dopamine, epinephrine, norepinephrine, weight, blood pressure, high sensitivity C-reactive protein. There was a decrease in trait anxiety (p = 0.004), an increase in quality of life (p = 0.03), and a decrease in insulin-like growth factor-1 (p = 0.01) and dopamine (p = 0.02) observed between pre- and postintervention measurements. Binaural beat technology may exhibit positive effect on self-reported psychologic measures, especially anxiety. Further research is warranted to explore the effects on anxiety using a larger, randomized and controlled trial.

Binaural beats increase interhemispheric alpha-band coherence between auditory cortices.

Science.gov (United States)

Solcà, Marco; Mottaz, Anaïs; Guggisberg, Adrian G

2016-02-01

Binaural beats (BBs) are an auditory illusion occurring when two tones of slightly different frequency are presented separately to each ear. BBs have been suggested to alter physiological and cognitive processes through synchronization of the brain hemispheres. To test this, we recorded electroencephalograms (EEG) at rest and while participants listened to BBs or a monaural control condition during which both tones were presented to both ears. We calculated for each condition the interhemispheric coherence, which expressed the synchrony between neural oscillations of both hemispheres. Compared to monaural beats and resting state, BBs enhanced interhemispheric coherence between the auditory cortices. Beat frequencies in the alpha (10 Hz) and theta (4 Hz) frequency range both increased interhemispheric coherence selectively at alpha frequencies. In a second experiment, we evaluated whether this coherence increase has a behavioral aftereffect on binaural listening. No effects were observed in a dichotic digit task performed immediately after BBs presentation. Our results suggest that BBs enhance alpha-band oscillation synchrony between the auditory cortices during auditory stimulation. This effect seems to reflect binaural integration rather than entrainment. Copyright © 2015 Elsevier B.V. All rights reserved.

The effect of different cochlear implant microphones on acoustic hearing individuals’ binaural benefits for speech perception in noise

Science.gov (United States)

Aronoff, Justin M.; Freed, Daniel J.; Fisher, Laurel M.; Pal, Ivan; Soli, Sigfrid D.

2011-01-01

Objectives Cochlear implant microphones differ in placement, frequency response, and other characteristics such as whether they are directional. Although normal hearing individuals are often used as controls in studies examining cochlear implant users’ binaural benefits, the considerable differences across cochlear implant microphones make such comparisons potentially misleading. The goal of this study was to examine binaural benefits for speech perception in noise for normal hearing individuals using stimuli processed by head-related transfer functions (HRTFs) based on the different cochlear implant microphones. Design HRTFs were created for different cochlear implant microphones and used to test participants on the Hearing in Noise Test. Experiment 1 tested cochlear implant users and normal hearing individuals with HRTF-processed stimuli and with sound field testing to determine whether the HRTFs adequately simulated sound field testing. Experiment 2 determined the measurement error and performance-intensity function for the Hearing in Noise Test with normal hearing individuals listening to stimuli processed with the various HRTFs. Experiment 3 compared normal hearing listeners’ performance across HRTFs to determine how the HRTFs affected performance. Experiment 4 evaluated binaural benefits for normal hearing listeners using the various HRTFs, including ones that were modified to investigate the contributions of interaural time and level cues. Results The results indicated that the HRTFs adequately simulated sound field testing for the Hearing in Noise Test. They also demonstrated that the test-retest reliability and performance-intensity function were consistent across HRTFs, and that the measurement error for the test was 1.3 dB, with a change in signal-to-noise ratio of 1 dB reflecting a 10% change in intelligibility. There were significant differences in performance when using the various HRTFs, with particularly good thresholds for the HRTF based on the

More attentional focusing through binaural beats: Evidence from the global-local task

OpenAIRE

Colzato, L.S.; Barone, H.; Sellaro, R.; Hommel, B.

2017-01-01

A recent study showed that binaural beats have an impact on the efficiency of allocating attention over time. We were interested to see whether this impact affects attentional focusing or, even further, the top-down control over irrelevant information. Healthy adults listened to gamma-frequency (40?Hz) binaural beats, which are assumed to increase attentional concentration, or a constant tone of 340?Hz (control condition) for 3?min before and during a global?local task. While the size of the ...

Monaural and binaural contributions to interaural-level-difference sensitivity in human auditory cortex.

Science.gov (United States)

Stecker, G Christopher; McLaughlin, Susan A; Higgins, Nathan C

2015-10-15

Whole-brain functional magnetic resonance imaging was used to measure blood-oxygenation-level-dependent (BOLD) responses in human auditory cortex (AC) to sounds with intensity varying independently in the left and right ears. Echoplanar images were acquired at 3 Tesla with sparse image acquisition once per 12-second block of sound stimulation. Combinations of binaural intensity and stimulus presentation rate were varied between blocks, and selected to allow measurement of response-intensity functions in three configurations: monaural 55-85 dB SPL, binaural 55-85 dB SPL with intensity equal in both ears, and binaural with average binaural level of 70 dB SPL and interaural level differences (ILD) ranging ±30 dB (i.e., favoring the left or right ear). Comparison of response functions equated for contralateral intensity revealed that BOLD-response magnitudes (1) generally increased with contralateral intensity, consistent with positive drive of the BOLD response by the contralateral ear, (2) were larger for contralateral monaural stimulation than for binaural stimulation, consistent with negative effects (e.g., inhibition) of ipsilateral input, which were strongest in the left hemisphere, and (3) also increased with ipsilateral intensity when contralateral input was weak, consistent with additional, positive, effects of ipsilateral stimulation. Hemispheric asymmetries in the spatial extent and overall magnitude of BOLD responses were generally consistent with previous studies demonstrating greater bilaterality of responses in the right hemisphere and stricter contralaterality in the left hemisphere. Finally, comparison of responses to fast (40/s) and slow (5/s) stimulus presentation rates revealed significant rate-dependent adaptation of the BOLD response that varied across ILD values. Copyright © 2015. Published by Elsevier Inc.

Exploiting deep neural networks and head movements for binaural localisation of multiple speakers in reverberant conditions

DEFF Research Database (Denmark)

Ma, Ning; Brown, Guy J.; May, Tobias

2015-01-01

This paper presents a novel machine-hearing system that exploits deep neural networks (DNNs) and head movements for binaural localisation of multiple speakers in reverberant conditions. DNNs are used to map binaural features, consisting of the complete crosscorrelation function (CCF) and interaural...

Hearing aid controlled by binaural source localizer

NARCIS (Netherlands)

2009-01-01

An adaptive directional hearing aid system comprising a left hearing aid and a right hearing aid, wherein a binaural acoustic source localizer is located in the left hearing aid or in the right hearing aid or in a separate body- worn device connected wirelessly to the left hearing aid and the right

Interaural delay sensitivity and the classification of low best-frequency binaural responses in the inferior colliculus of the guinea pig.

Science.gov (United States)

McAlpine, D; Jiang, D; Palmer, A R

1996-08-01

Monaural and binaural response properties of single units in the inferior colliculus (IC) of the guinea pig were investigated. Neurones were classified according to the effect of monaural stimulation of either ear alone and the effect of binaural stimulation. The majority (309/334) of IC units were excited (E) by stimulation of the contralateral ear, of which 41% (127/309) were also excited by monaural ipsilateral stimulation (EE), and the remainder (182/309) were unresponsive to monaural ipsilateral stimulation (EO). For units with best frequencies (BF) up to 3 kHz, similar proportions of EE and EO units were observed. Above 3 kHz, however, significantly more EO than EE units were observed. Units were also classified as either facilitated (F), suppressed (S), or unaffected (O) by binaural stimulation. More EO than EE units were suppressed or unaffected by binaural stimulation, and more EE than EO units were facilitated. There were more EO/S units above 1.5 kHz than below. Binaural beats were used to examine the interaural delay sensitivity of low-BF (BF binaural facilitation, whilst those with larger BPs generally showed binaural suppression. The classification of units based upon binaural stimulation with BF tones was consistent with their interaural-delay sensitivity. Characteristic delays (CD) were examined for 96 low-BF units. A clear relationship between BF and CD was observed. CDs of units with very low BFs (binaural processing in the guinea pig at low frequencies is similar to that reported in all other species studied. However, the dependence of CD on BF would suggest that the delay line system that sets up the interaural-delay sensitivity in the lower brainstem varies across frequency as well as within each frequency band.

Usage of measured reverberation tail in a binaural room impulse response synthesis

DEFF Research Database (Denmark)

Markovic, Milos; Olesen, Søren Krarup; Madsen, Esben

2011-01-01

The aim of the modern communication technologies is an immersive experience. One of the applications that should provide the feeling of being together and sharing the same environment during the communication process is BEAMING. The goal of this paper is to improve audible spatial impression...... utilizing correct acoustical properties of the specific environments. Binaural room impulse response (BRIR) synthesis represents one of the main tasks in the binaural auralization. When the BRIRs are simulated, high order reflections (reverberation tail) are usually modeled statistically because of the high...

The Binaural Interaction Component in Barn Owl (Tyto alba) Presents few Differences to Mammalian Data.

Science.gov (United States)

Palanca-Castan, Nicolas; Laumen, Geneviève; Reed, Darrin; Köppl, Christine

2016-12-01

The auditory brainstem response (ABR) is an evoked potential that reflects the responses to sound by brainstem neural centers. The binaural interaction component (BIC) is obtained by subtracting the sum of the monaural ABR responses from the binaural response. Its latency and amplitude change in response to variations in binaural cues. The BIC is thus thought to reflect the activity of binaural nuclei and is used to non-invasively test binaural processing. However, any conclusions are limited by a lack of knowledge of the relevant processes at the level of individual neurons. The aim of this study was to characterize the ABR and BIC in the barn owl, an animal where the ITD-processing neural circuits are known in great detail. We recorded ABR responses to chirps and to 1 and 4 kHz tones from anesthetized barn owls. General characteristics of the barn owl ABR were similar to those observed in other bird species. The most prominent peak of the BIC was associated with nucleus laminaris and is thus likely to reflect the known processes of ITD computation in this nucleus. However, the properties of the BIC were very similar to previously published mammalian data and did not reveal any specific diagnostic features. For example, the polarity of the BIC was negative, which indicates a smaller response to binaural stimulation than predicted by the sum of monaural responses. This is contrary to previous predictions for an excitatory-excitatory system such as nucleus laminaris. Similarly, the change in BIC latency with varying ITD was not distinguishable from mammalian data. Contrary to previous predictions, this behavior appears unrelated to the known underlying neural delay-line circuitry. In conclusion, the generation of the BIC is currently inadequately understood and common assumptions about the BIC need to be reconsidered when interpreting such measurements.

Binaural speech enhancement using a codebook based approach

DEFF Research Database (Denmark)

Kavalekalam, Mathew Shaji; Christensen, Mads Græsbøll; Boldt, Jesper B.

2016-01-01

term predictor (STP) parameters using a codebook based approach, when we have access to binaural noisy signals. The estimated STP parameters are subsequently used for enhancement in a dual channel scenario. Objective measures indicate, that the proposed method is able to improve the speech...

Efektivita binaurálních rytmů pro navození relaxačních stavů

OpenAIRE

VEJBOR, Roman

2015-01-01

This bachelor thesis deals with studies of binaural beats, specially their effect on the signal, measured by EEG. The aim of this study was to investigate if binaural beats are an effective tool to induce relaxation states, namely increased brain actvity in the alfa and theta frequencies. The theoretical part describes electrical activity of the brain, the issue of binaural beats and researches related to this issue. Following several chapters are about neuroplasticity as a possible aspect of...

Audibility of time switching in dynamic binaural synthesis

DEFF Research Database (Denmark)

Hoffmann, Pablo F.F.; Møller, Henrik

2005-01-01

In binaural synthesis, signals are convolved with head-related transfer functions (HRTFs). In dynamic systems, the update is often done by cross- fading between signals that have been filtered in parallel with two HRTFs. An alternative to cross-fading that is attractive in terms of computing power...

Binaural segregation in multisource reverberant environments.

Science.gov (United States)

Roman, Nicoleta; Srinivasan, Soundararajan; Wang, DeLiang

2006-12-01

In a natural environment, speech signals are degraded by both reverberation and concurrent noise sources. While human listening is robust under these conditions using only two ears, current two-microphone algorithms perform poorly. The psychological process of figure-ground segregation suggests that the target signal is perceived as a foreground while the remaining stimuli are perceived as a background. Accordingly, the goal is to estimate an ideal time-frequency (T-F) binary mask, which selects the target if it is stronger than the interference in a local T-F unit. In this paper, a binaural segregation system that extracts the reverberant target signal from multisource reverberant mixtures by utilizing only the location information of target source is proposed. The proposed system combines target cancellation through adaptive filtering and a binary decision rule to estimate the ideal T-F binary mask. The main observation in this work is that the target attenuation in a T-F unit resulting from adaptive filtering is correlated with the relative strength of target to mixture. A comprehensive evaluation shows that the proposed system results in large SNR gains. In addition, comparisons using SNR as well as automatic speech recognition measures show that this system outperforms standard two-microphone beamforming approaches and a recent binaural processor.

Diversity of bilateral synaptic assemblies for binaural computation in midbrain single neurons.

Science.gov (United States)

He, Na; Kong, Lingzhi; Lin, Tao; Wang, Shaohui; Liu, Xiuping; Qi, Jiyao; Yan, Jun

2017-11-01

Binaural hearing confers many beneficial functions but our understanding of its underlying neural substrates is limited. This study examines the bilateral synaptic assemblies and binaural computation (or integration) in the central nucleus of the inferior colliculus (ICc) of the auditory midbrain, a key convergent center. Using in-vivo whole-cell patch-clamp, the excitatory and inhibitory postsynaptic potentials (EPSPs/IPSPs) of single ICc neurons to contralateral, ipsilateral and bilateral stimulation were recorded. According to the contralateral and ipsilateral EPSP/IPSP, 7 types of bilateral synaptic assemblies were identified. These include EPSP-EPSP (EE), E-IPSP (EI), E-no response (EO), II, IE, IO and complex-mode (CM) neurons. The CM neurons showed frequency- and/or amplitude-dependent EPSPs/IPSPs to contralateral or ipsilateral stimulation. Bilateral stimulation induced EPSPs/IPSPs that could be larger than (facilitation), similar to (ineffectiveness) or smaller than (suppression) those induced by contralateral stimulation. Our findings have allowed our group to characterize novel neural circuitry for binaural computation in the midbrain. Copyright © 2017 Elsevier B.V. All rights reserved.

The Physiological Basis and Clinical Use of the Binaural Interaction Component of the Auditory Brainstem Response

Science.gov (United States)

Klump, Georg M.; Tollin, Daniel J.

2016-01-01

The auditory brainstem response (ABR) is a sound-evoked non-invasively measured electrical potential representing the sum of neuronal activity in the auditory brainstem and midbrain. ABR peak amplitudes and latencies are widely used in human and animal auditory research and for clinical screening. The binaural interaction component (BIC) of the ABR stands for the difference between the sum of the monaural ABRs and the ABR obtained with binaural stimulation. The BIC comprises a series of distinct waves, the largest of which (DN1) has been used for evaluating binaural hearing in both normal hearing and hearing-impaired listeners. Based on data from animal and human studies, we discuss the possible anatomical and physiological bases of the BIC (DN1 in particular). The effects of electrode placement and stimulus characteristics on the binaurally evoked ABR are evaluated. We review how inter-aural time and intensity differences affect the BIC and, analyzing these dependencies, draw conclusion about the mechanism underlying the generation of the BIC. Finally, the utility of the BIC for clinical diagnoses are summarized. PMID:27232077

Use of binaural beat tapes for treatment of anxiety: a pilot study of tape preference and outcomes.

Science.gov (United States)

Le Scouarnec, R P; Poirier, R M; Owens, J E; Gauthier, J; Taylor, A G; Foresman, P A

2001-01-01

Recent studies and anecdotal reports suggest that binaural auditory beats can affect mood, performance on vigilance tasks, and anxiety. To determine whether mildly anxious people would report decreased anxiety after listening daily for 1 month to tapes imbedded with tones that create binaural beats, and whether they would show a definite tape preference among 3 tapes. A 1-group pre-posttest pilot study. Patients' homes. A volunteer sample of 15 mildly anxious patients seen in the Clinique Psyché, Montreal, Quebec. Participants were asked to listen at least 5 times weekly for 4 weeks to 1 or more of 3 music tapes containing tones that produce binaural beats in the electroencephalogram delta/theta frequency range. Participants also were asked to record tape usage, tape preference, and anxiety ratings in a journal before and after listening to the tape or tapes. Anxiety ratings before and after tape listening, pre- and post-study State-Trait Anxiety Inventory scores, and tape preferences documented in daily journals. Listening to the binaural beat tapes resulted in a significant reduction in the anxiety score reported daily in patients' diaries. The number of times participants listened to the tapes in 4 weeks ranged from 10 to 17 (an average of 1.4 to 2.4 times per week) for approximately 30 minutes per session. End-of-study tape preferences indicated that slightly more participants preferred tape B, with its pronounced and extended patterns of binaural beats, over tapes A and C. Changes in pre- and posttest listening State-Trait Anxiety Inventory scores trended toward a reduction of anxiety, but these differences were not statistically significant. Listening to binaural beat tapes in the delta/theta electroencephalogram range may be beneficial in reducing mild anxiety. Future studies should account for music preference among participants and include age as a factor in outcomes, incentives to foster tape listening, and a physiologic measure of anxiety reduction. A

The effect of audiovisual and binaural listening on the acceptable noise level (ANL): establishing an ANL conceptual model.

Science.gov (United States)

Wu, Yu-Hsiang; Stangl, Elizabeth; Pang, Carol; Zhang, Xuyang

2014-02-01

Little is known regarding the acoustic features of a stimulus used by listeners to determine the acceptable noise level (ANL). Features suggested by previous research include speech intelligibility (noise is unacceptable when it degrades speech intelligibility to a certain degree; the intelligibility hypothesis) and loudness (noise is unacceptable when the speech-to-noise loudness ratio is poorer than a certain level; the loudness hypothesis). The purpose of the study was to investigate if speech intelligibility or loudness is the criterion feature that determines ANL. To achieve this, test conditions were chosen so that the intelligibility and loudness hypotheses would predict different results. In Experiment 1, the effect of audiovisual (AV) and binaural listening on ANL was investigated; in Experiment 2, the effect of interaural correlation (ρ) on ANL was examined. A single-blinded, repeated-measures design was used. Thirty-two and twenty-five younger adults with normal hearing participated in Experiments 1 and 2, respectively. In Experiment 1, both ANL and speech recognition performance were measured using the AV version of the Connected Speech Test (CST) in three conditions: AV-binaural, auditory only (AO)-binaural, and AO-monaural. Lipreading skill was assessed using the Utley lipreading test. In Experiment 2, ANL and speech recognition performance were measured using the Hearing in Noise Test (HINT) in three binaural conditions, wherein the interaural correlation of noise was varied: ρ = 1 (N(o)S(o) [a listening condition wherein both speech and noise signals are identical across two ears]), -1 (NπS(o) [a listening condition wherein speech signals are identical across two ears whereas the noise signals of two ears are 180 degrees out of phase]), and 0 (N(u)S(o) [a listening condition wherein speech signals are identical across two ears whereas noise signals are uncorrelated across ears]). The results were compared to the predictions made based on the

Age-Related Changes in Binaural Interaction at Brainstem Level

NARCIS (Netherlands)

Yper, L.N. Van; Vermeire, K.; Vel, E.F. De; Beynon, A.J.; Dhooge, I.J.

2016-01-01

OBJECTIVES: Age-related hearing loss hampers the ability to understand speech in adverse listening conditions. This is attributed to a complex interaction of changes in the peripheral and central auditory system. One aspect that may deteriorate across the lifespan is binaural interaction. The

Effectiveness of binaural beats in reducing preoperative dental anxiety.

Science.gov (United States)

Isik, B K; Esen, A; Büyükerkmen, B; Kilinç, A; Menziletoglu, D

2017-07-01

Binaural beats are an auditory illusion perceived when two different pure-tone sine waves are presented one to each ear at a steady intensity and frequency. We evaluated their effectiveness in reducing preoperative anxiety in dentistry. Sixty patients (30 in each group) who were to have impacted third molars removed were studied (experimental group: 20 women and 10 men, mean (range) age 24 (18-35) years, and control group: 22 women and 8 men, mean (range) age 28 (15-47) years). All patients were fully informed about the operation preoperatively, and their anxiety recorded on a visual analogue scale (VAS). The local anaesthetic was given and the patients waited for 10minutes, during which those in the experimental group were asked to listen to binaural beats through stereo earphones (200Hz for the left ear and 209.3Hz for the right ear). No special treatment was given to the control group. In both groups anxiety was then recorded again, and the tooth removed in the usual way. The paired t test and t test were used to assess the significance of differences between groups. The degree of anxiety in the control group was unchanged after the second measurement (p=0.625), while that in the experimental group showed a significant reduction in anxiety (p=0.001). We conclude that binaural beats may be useful in reducing preoperative anxiety in dentistry. Copyright © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Comparing Binaural Pre-processing Strategies I: Instrumental Evaluation.

Science.gov (United States)

Baumgärtel, Regina M; Krawczyk-Becker, Martin; Marquardt, Daniel; Völker, Christoph; Hu, Hongmei; Herzke, Tobias; Coleman, Graham; Adiloğlu, Kamil; Ernst, Stephan M A; Gerkmann, Timo; Doclo, Simon; Kollmeier, Birger; Hohmann, Volker; Dietz, Mathias

2015-12-30

In a collaborative research project, several monaural and binaural noise reduction algorithms have been comprehensively evaluated. In this article, eight selected noise reduction algorithms were assessed using instrumental measures, with a focus on the instrumental evaluation of speech intelligibility. Four distinct, reverberant scenarios were created to reflect everyday listening situations: a stationary speech-shaped noise, a multitalker babble noise, a single interfering talker, and a realistic cafeteria noise. Three instrumental measures were employed to assess predicted speech intelligibility and predicted sound quality: the intelligibility-weighted signal-to-noise ratio, the short-time objective intelligibility measure, and the perceptual evaluation of speech quality. The results show substantial improvements in predicted speech intelligibility as well as sound quality for the proposed algorithms. The evaluated coherence-based noise reduction algorithm was able to provide improvements in predicted audio signal quality. For the tested single-channel noise reduction algorithm, improvements in intelligibility-weighted signal-to-noise ratio were observed in all but the nonstationary cafeteria ambient noise scenario. Binaural minimum variance distortionless response beamforming algorithms performed particularly well in all noise scenarios. © The Author(s) 2015.

Measures of extents of laterality for high-frequency ``transposed'' stimuli under conditions of binaural interference

Science.gov (United States)

Bernstein, Leslie R.; Trahiotis, Constantine

2005-09-01

Our purpose in this study was to determine whether across-frequency binaural interference would occur if ITD-based extents of laterality were measured using high-frequency transposed stimuli as targets. The results of an earlier study [L. R. Bernstein and C. Trahiotis, J. Acoust. Soc. Am. 116, 3062-3069 (2004)], which focused on threshold-ITDs, rather than extents of laterality, suggested that high-frequency transposed stimuli might be ``immune'' to binaural interference effects resulting from the addition of a spectrally remote, low-frequency interferer. In contrast to the earlier findings, the data from this study indicate that high-frequency transposed targets are susceptible to binaural interference. Nevertheless, high-frequency transposed targets, even when presented along with an interferer, yielded greater extents of ITD-based laterality than did high-frequency Gaussian noise targets presented in isolation. That is, the ``enhanced potency'' of ITDs conveyed by transposed stimuli persisted, even in the presence of a low-frequency interferer. Predictions made using an extension of the model of Heller and Trahiotis [L. M. Heller and C. Trahiotis, J. Acoust. Soc. Am. 99, 3632-3637 (1996)] accounted well for across-frequency binaural interference obtained with conventional Gaussian noise targets but, in all but one case, overpredicted the amounts of interference found with the transposed targets.

Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal

OpenAIRE

Patrick eMcConnell; Patrick eMcConnell; Brett eFroeliger; Eric L. Garland; Jeffrey C. Ives; Gary A. Sforzo

2014-01-01

Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation), few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics (heart-rate variability (HRV)) during post-exercise relaxation...

Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal

OpenAIRE

McConnell, Patrick A.; Froeliger, Brett; Garland, Eric L.; Ives, Jeffrey C.; Sforzo, Gary A.

2014-01-01

Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation), few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics [heart rate variability (HRV)] during post-exercise relaxation...

Comparison between bilateral cochlear implants and Neurelec Digisonic(®) SP Binaural cochlear implant: speech perception, sound localization and patient self-assessment.

Science.gov (United States)

Bonnard, Damien; Lautissier, Sylvie; Bosset-Audoit, Amélie; Coriat, Géraldine; Beraha, Max; Maunoury, Antoine; Martel, Jacques; Darrouzet, Vincent; Bébéar, Jean-Pierre; Dauman, René

2013-01-01

An alternative to bilateral cochlear implantation is offered by the Neurelec Digisonic(®) SP Binaural cochlear implant, which allows stimulation of both cochleae within a single device. The purpose of this prospective study was to compare a group of Neurelec Digisonic(®) SP Binaural implant users (denoted BINAURAL group, n = 7) with a group of bilateral adult cochlear implant users (denoted BILATERAL group, n = 6) in terms of speech perception, sound localization, and self-assessment of health status and hearing disability. Speech perception was assessed using word recognition at 60 dB SPL in quiet and in a 'cocktail party' noise delivered through five loudspeakers in the hemi-sound field facing the patient (signal-to-noise ratio = +10 dB). The sound localization task was to determine the source of a sound stimulus among five speakers positioned between -90° and +90° from midline. Change in health status was assessed using the Glasgow Benefit Inventory and hearing disability was evaluated with the Abbreviated Profile of Hearing Aid Benefit. Speech perception was not statistically different between the two groups, even though there was a trend in favor of the BINAURAL group (mean percent word recognition in the BINAURAL and BILATERAL groups: 70 vs. 56.7% in quiet, 55.7 vs. 43.3% in noise). There was also no significant difference with regard to performance in sound localization and self-assessment of health status and hearing disability. On the basis of the BINAURAL group's performance in hearing tasks involving the detection of interaural differences, implantation with the Neurelec Digisonic(®) SP Binaural implant may be considered to restore effective binaural hearing. Based on these first comparative results, this device seems to provide benefits similar to those of traditional bilateral cochlear implantation, with a new approach to stimulate both auditory nerves. Copyright © 2013 S. Karger AG, Basel.

Audio system using binaural synthesis for multimodal telepresence applications

DEFF Research Database (Denmark)

Madsen, Esben; Markovic, Milos; Olesen, Søren Krarup

2013-01-01

are implemented in a distributed manner. Body-tracking of all participants is provided through the system for the purpose of using binaural synthesis for directional sound. Head-worn microphones are used to capture sound, and the visitor is provided with directional sound through headphones. The visitor...

Effect of simultaneous exposure to occupational noise and cigarette smoke on binaural hearing impairment

Directory of Open Access Journals (Sweden)

Saber Mohammadi

2010-01-01

Full Text Available In recent years, it has been postulated that cigarette smoking can aggravate noise-induced hearing loss. In this study, we aimed to assess the effect of concurrent exposure to cigarette smoke and occupational noise on binaural hearing impairment (BHI. In an analytic study on the workers of a large wagon manufacturing company in 2007, 622 male workers (252 smokers and 370 non-smokers, matched for other variables participated and their BHI was compared. BHI was significantly higher in smokers than in non-smokers (odds ratio= 5.6, P < 0.001, 95% CI =3.4-9.4. Logistic regression confirmed this significant difference as well, and showed a direct relationship between the amount of BHI and pack/years of smoking. Cigarette smoking accompanied by exposure to workplace noise may play a role in causing binaural hearing impairment, so giving up or decreasing the amount of smoking may prevent or at least delay binaural hearing impairment, and eventually reduce its compensation costs.

Spatio-Temporal Analysis of Urban Acoustic Environments with Binaural Psycho-Acoustical Considerations for IoT-Based Applications.

Science.gov (United States)

Segura-Garcia, Jaume; Navarro-Ruiz, Juan Miguel; Perez-Solano, Juan J; Montoya-Belmonte, Jose; Felici-Castell, Santiago; Cobos, Maximo; Torres-Aranda, Ana M

2018-02-26

Sound pleasantness or annoyance perceived in urban soundscapes is a major concern in environmental acoustics. Binaural psychoacoustic parameters are helpful to describe generic acoustic environments, as it is stated within the ISO 12913 framework. In this paper, the application of a Wireless Acoustic Sensor Network (WASN) to evaluate the spatial distribution and the evolution of urban acoustic environments is described. Two experiments are presented using an indoor and an outdoor deployment of a WASN with several nodes using an Internet of Things (IoT) environment to collect audio data and calculate meaningful parameters such as the sound pressure level, binaural loudness and binaural sharpness. A chunk of audio is recorded in each node periodically with a microphone array and the binaural rendering is conducted by exploiting the estimated directional characteristics of the incoming sound by means of DOA estimation. Each node computes the parameters in a different location and sends the values to a cloud-based broker structure that allows spatial statistical analysis through Kriging techniques. A cross-validation analysis is also performed to confirm the usefulness of the proposed system.

Evaluation of dynamic binaural reproduction system for live transmitted xylophone recording

DEFF Research Database (Denmark)

Madsen, Esben; Markovic, Milos; Olesen, Søren Krarup

2012-01-01

For a special teaching application of the telepresence research project BEAMING, a scenario of a remote teacher (the Visitor) teaching a local student to play a xylophone through an embodiment is defined. In order to achieve this, a system is required to record, transmit and render the sound....... Finally head tracking allows for a dynamic binaural rendering of the xylophone sound. The goal of this paper is to evaluate the realism of this virtual (auditory) representation of a real xylophone. A listening test is designed to compare characteristics of a real physical xylophone in front...... of the listener with a rendering using the described system. The evaluation is done with a basis in methods previously used for evaluating the subjective sensation of presence in virtual reality systems, mainly based on questionnaires....

Response of cat inferior colliculus neurons to binaural beat stimuli: possible mechanisms for sound localization.

Science.gov (United States)

Kuwada, S; Yin, T C; Wickesberg, R E

1979-11-02

The interaural phase sensitivity of neurons was studied through the use of binaural beat stimuli. The response of most cells was phase-locked to the beat frequency, which provides a possible neural correlate to the human sensation of binaural beats. In addition, this stimulus allowed the direction and rate of interaural phase change to be varied. Some neurons in our sample responded selectively to manipulations of these two variables, which suggests a sensitivity to direction or speed of movement.

Perceptual consequences of different signal changes due to binaural noise reduction: do hearing loss and working memory capacity play a role?

Science.gov (United States)

Neher, Tobias; Grimm, Giso; Hohmann, Volker

2014-01-01

In a previous study, ) investigated whether pure-tone average (PTA) hearing loss and working memory capacity (WMC) modulate benefit from different binaural noise reduction (NR) settings. Results showed that listeners with smaller WMC preferred strong over moderate NR even at the expense of poorer speech recognition due to greater speech distortion (SD), whereas listeners with larger WMC did not. To enable a better understanding of these findings, the main aims of the present study were (1) to explore the perceptual consequences of changes to the signal mixture, target speech, and background noise caused by binaural NR, and (2) to determine whether response to these changes varies with WMC and PTA. As in the previous study, four age-matched groups of elderly listeners (with N = 10 per group) characterized by either mild or moderate PTAs and either better or worse performance on a visual measure of WMC participated. Five processing conditions were tested, which were based on the previously used (binaural coherence-based) NR scheme designed to attenuate diffuse signal components at mid to high frequencies. The five conditions differed in terms of the type of processing that was applied (no NR, strong NR, or strong NR with restoration of the long-term stimulus spectrum) and in terms of whether the target speech and background noise were processed in the same manner or whether one signal was left unprocessed while the other signal was processed with the gains computed for the signal mixture. Comparison across these conditions allowed assessing the effects of changes in high-frequency audibility (HFA), SD, and noise attenuation and distortion (NAD). Outcome measures included a dual-task paradigm combining speech recognition with a visual reaction time (VRT) task as well as ratings of perceived effort and overall preference. All measurements were carried out using headphone simulations of a frontal target speaker in a busy cafeteria. Relative to no NR, strong NR was found

Spatio-Temporal Analysis of Urban Acoustic Environments with Binaural Psycho-Acoustical Considerations for IoT-Based Applications

Directory of Open Access Journals (Sweden)

Jaume Segura-Garcia

2018-02-01

Full Text Available Sound pleasantness or annoyance perceived in urban soundscapes is a major concern in environmental acoustics. Binaural psychoacoustic parameters are helpful to describe generic acoustic environments, as it is stated within the ISO 12913 framework. In this paper, the application of a Wireless Acoustic Sensor Network (WASN to evaluate the spatial distribution and the evolution of urban acoustic environments is described. Two experiments are presented using an indoor and an outdoor deployment of a WASN with several nodes using an Internet of Things (IoT environment to collect audio data and calculate meaningful parameters such as the sound pressure level, binaural loudness and binaural sharpness. A chunk of audio is recorded in each node periodically with a microphone array and the binaural rendering is conducted by exploiting the estimated directional characteristics of the incoming sound by means of DOA estimation. Each node computes the parameters in a different location and sends the values to a cloud-based broker structure that allows spatial statistical analysis through Kriging techniques. A cross-validation analysis is also performed to confirm the usefulness of the proposed system.

Predicting the benefit of binaural cue preservation in bilateral directional processing schemes for listeners with impaired hearing

DEFF Research Database (Denmark)

Brand, Thomas; Hauth, Christopher; Wagener, Kirsten C.

2018-01-01

Linked pairs of hearing aids offer various possibilities for directional processing providing adjustable trade-off between improving signal-to-noise ratio and preserving binaural listening. The benefit depends on the processing scheme, the acoustic scenario, and the listener’s ability to exploit...... fine structure. BSIM revealed a benefit due to binaural processing in well-performing listeners when processing provided low-frequency interaural timing cues....

Range dependent characteristics in the head-related transfer functions of a bat-head cast: part 2. Binaural characteristics

International Nuclear Information System (INIS)

Kim, S; Allen, R; Rowan, D

2012-01-01

Further innovations in bio-inspired engineering based on biosonar systems, such as bats, may arise from more detailed understanding of the underlying acoustic processes. This includes the range-dependent properties of bat heads and ears, particularly at the higher frequencies of bat vocalizations. In a companion paper Kim et al (2012 Bioinspir. Biomim.), range-dependent head-related transfer functions of a bat head cast were investigated up to 100 kHz at either ear (i.e. monaural features). The current paper extends this to consider range-dependent spectral and temporal disparities between the two ears (i.e. binaural features), using experimental data and a spherical model of a bat head to provide insights into the physical basis for these features. It was found that binaural temporal and high-frequency binaural spectral features are approximately independent of distance, having the effect of decreasing their angular resolution at close range. In contrast, low-frequency binaural spectral features are strongly distance-dependent, such that angular sensitivity can be maintained by lowering the frequency of the echolocation emission at close range. Together with the companion paper Kim et al, we speculate that distance-dependent low-frequency monaural and binaural features at short range might help explain why some species of bats that drop the frequency of their calls on target approach while approaching a target. This also provides an impetus for the design of effective emissions in sonar engineering applied to similar tasks. (paper)

Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity.

Science.gov (United States)

Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

2017-01-01

A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG) was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS) before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state.

Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity

Directory of Open Access Journals (Sweden)

Nantawachara Jirakittayakorn

2017-06-01

Full Text Available A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state.

Structural Changes and Lack of HCN1 Channels in the Binaural Auditory Brainstem of the Naked Mole-Rat (Heterocephalus glaber).

Science.gov (United States)

Gessele, Nikodemus; Garcia-Pino, Elisabet; Omerbašić, Damir; Park, Thomas J; Koch, Ursula

2016-01-01

Naked mole-rats (Heterocephalus glaber) live in large eu-social, underground colonies in narrow burrows and are exposed to a large repertoire of communication signals but negligible binaural sound localization cues, such as interaural time and intensity differences. We therefore asked whether monaural and binaural auditory brainstem nuclei in the naked mole-rat are differentially adjusted to this acoustic environment. Using antibody stainings against excitatory and inhibitory presynaptic structures, namely the vesicular glutamate transporter VGluT1 and the glycine transporter GlyT2 we identified all major auditory brainstem nuclei except the superior paraolivary nucleus in these animals. Naked mole-rats possess a well structured medial superior olive, with a similar synaptic arrangement to interaural-time-difference encoding animals. The neighboring lateral superior olive, which analyzes interaural intensity differences, is large and elongated, whereas the medial nucleus of the trapezoid body, which provides the contralateral inhibitory input to these binaural nuclei, is reduced in size. In contrast, the cochlear nucleus, the nuclei of the lateral lemniscus and the inferior colliculus are not considerably different when compared to other rodent species. Most interestingly, binaural auditory brainstem nuclei lack the membrane-bound hyperpolarization-activated channel HCN1, a voltage-gated ion channel that greatly contributes to the fast integration times in binaural nuclei of the superior olivary complex in other species. This suggests substantially lengthened membrane time constants and thus prolonged temporal integration of inputs in binaural auditory brainstem neurons and might be linked to the severely degenerated sound localization abilities in these animals.

Structural Changes and Lack of HCN1 Channels in the Binaural Auditory Brainstem of the Naked Mole-Rat (Heterocephalus glaber.

Directory of Open Access Journals (Sweden)

Nikodemus Gessele

Full Text Available Naked mole-rats (Heterocephalus glaber live in large eu-social, underground colonies in narrow burrows and are exposed to a large repertoire of communication signals but negligible binaural sound localization cues, such as interaural time and intensity differences. We therefore asked whether monaural and binaural auditory brainstem nuclei in the naked mole-rat are differentially adjusted to this acoustic environment. Using antibody stainings against excitatory and inhibitory presynaptic structures, namely the vesicular glutamate transporter VGluT1 and the glycine transporter GlyT2 we identified all major auditory brainstem nuclei except the superior paraolivary nucleus in these animals. Naked mole-rats possess a well structured medial superior olive, with a similar synaptic arrangement to interaural-time-difference encoding animals. The neighboring lateral superior olive, which analyzes interaural intensity differences, is large and elongated, whereas the medial nucleus of the trapezoid body, which provides the contralateral inhibitory input to these binaural nuclei, is reduced in size. In contrast, the cochlear nucleus, the nuclei of the lateral lemniscus and the inferior colliculus are not considerably different when compared to other rodent species. Most interestingly, binaural auditory brainstem nuclei lack the membrane-bound hyperpolarization-activated channel HCN1, a voltage-gated ion channel that greatly contributes to the fast integration times in binaural nuclei of the superior olivary complex in other species. This suggests substantially lengthened membrane time constants and thus prolonged temporal integration of inputs in binaural auditory brainstem neurons and might be linked to the severely degenerated sound localization abilities in these animals.

Early Studies of Binocular and Binaural Directions

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Nicholas J. Wade

2018-03-01

Full Text Available Understanding how the eyes work together to determine the direction of objects provided the impetus for examining integration of signals from the ears to locate sounds. However, the advantages of having two eyes were recorded long before those for two ears were appreciated. In part, this reflects the marked differences in how we can compare perception with one or two organs. It is easier to close one eye and examine monocular vision than to “close” one ear and study monaural hearing. Moreover, we can move our eyes either in the same or in opposite directions, but humans have no equivalent means of moving the ears in unison. Studies of binocular single vision can be traced back over two thousand years and they were implicitly concerned with visual directions from each eye. The location of any point in visual or auditory space can be described by specifying its direction and distance, from the vantage point of an observer. From the late 18th century experiments indicated that binocular direction involved an eye movement component and experimental studies of binaural direction commenced slightly later. However, these early binocular and binaural experiments were not incorporated into theoretical accounts until almost a century later. The early history of research on visual direction with two eyes is contrasted to that on auditory direction with two ears.

Binaural noise reduction via cue-preserving MMSE filter and adaptive-blocking-based noise PSD estimation

Science.gov (United States)

Azarpour, Masoumeh; Enzner, Gerald

2017-12-01

Binaural noise reduction, with applications for instance in hearing aids, has been a very significant challenge. This task relates to the optimal utilization of the available microphone signals for the estimation of the ambient noise characteristics and for the optimal filtering algorithm to separate the desired speech from the noise. The additional requirements of low computational complexity and low latency further complicate the design. A particular challenge results from the desired reconstruction of binaural speech input with spatial cue preservation. The latter essentially diminishes the utility of multiple-input/single-output filter-and-sum techniques such as beamforming. In this paper, we propose a comprehensive and effective signal processing configuration with which most of the aforementioned criteria can be met suitably. This relates especially to the requirement of efficient online adaptive processing for noise estimation and optimal filtering while preserving the binaural cues. Regarding noise estimation, we consider three different architectures: interaural (ITF), cross-relation (CR), and principal-component (PCA) target blocking. An objective comparison with two other noise PSD estimation algorithms demonstrates the superiority of the blocking-based noise estimators, especially the CR-based and ITF-based blocking architectures. Moreover, we present a new noise reduction filter based on minimum mean-square error (MMSE), which belongs to the class of common gain filters, hence being rigorous in terms of spatial cue preservation but also efficient and competitive for the acoustic noise reduction task. A formal real-time subjective listening test procedure is also developed in this paper. The proposed listening test enables a real-time assessment of the proposed computationally efficient noise reduction algorithms in a realistic acoustic environment, e.g., considering time-varying room impulse responses and the Lombard effect. The listening test outcome

A Diagonal-Steering-Based Binaural Beamforming Algorithm Incorporating a Diagonal Speech Localizer for Persons With Bilateral Hearing Impairment.

Science.gov (United States)

Lee, Jun Chang; Nam, Kyoung Won; Jang, Dong Pyo; Kim, In Young

2015-12-01

Previously suggested diagonal-steering algorithms for binaural hearing support devices have commonly assumed that the direction of the speech signal is known in advance, which is not always the case in many real circumstances. In this study, a new diagonal-steering-based binaural speech localization (BSL) algorithm is proposed, and the performances of the BSL algorithm and the binaural beamforming algorithm, which integrates the BSL and diagonal-steering algorithms, were evaluated using actual speech-in-noise signals in several simulated listening scenarios. Testing sounds were recorded in a KEMAR mannequin setup and two objective indices, improvements in signal-to-noise ratio (SNRi ) and segmental SNR (segSNRi ), were utilized for performance evaluation. Experimental results demonstrated that the accuracy of the BSL was in the 90-100% range when input SNR was -10 to +5 dB range. The average differences between the γ-adjusted and γ-fixed diagonal-steering algorithms (for -15 to +5 dB input SNR) in the talking in the restaurant scenario were 0.203-0.937 dB for SNRi and 0.052-0.437 dB for segSNRi , and in the listening while car driving scenario, the differences were 0.387-0.835 dB for SNRi and 0.259-1.175 dB for segSNRi . In addition, the average difference between the BSL-turned-on and the BSL-turned-off cases for the binaural beamforming algorithm in the listening while car driving scenario was 1.631-4.246 dB for SNRi and 0.574-2.784 dB for segSNRi . In all testing conditions, the γ-adjusted diagonal-steering and BSL algorithm improved the values of the indices more than the conventional algorithms. The binaural beamforming algorithm, which integrates the proposed BSL and diagonal-steering algorithm, is expected to improve the performance of the binaural hearing support devices in noisy situations. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Speech reception with different bilateral directional processing schemes: Influence of binaural hearing, audiometric asymmetry, and acoustic scenario.

Science.gov (United States)

Neher, Tobias; Wagener, Kirsten C; Latzel, Matthias

2017-09-01

Hearing aid (HA) users can differ markedly in their benefit from directional processing (or beamforming) algorithms. The current study therefore investigated candidacy for different bilateral directional processing schemes. Groups of elderly listeners with symmetric (N = 20) or asymmetric (N = 19) hearing thresholds for frequencies below 2 kHz, a large spread in the binaural intelligibility level difference (BILD), and no difference in age, overall degree of hearing loss, or performance on a measure of selective attention took part. Aided speech reception was measured using virtual acoustics together with a simulation of a linked pair of completely occluding behind-the-ear HAs. Five processing schemes and three acoustic scenarios were used. The processing schemes differed in the tradeoff between signal-to-noise ratio (SNR) improvement and binaural cue preservation. The acoustic scenarios consisted of a frontal target talker presented against two speech maskers from ±60° azimuth or spatially diffuse cafeteria noise. For both groups, a significant interaction between BILD, processing scheme, and acoustic scenario was found. This interaction implied that, in situations with lateral speech maskers, HA users with BILDs larger than about 2 dB profited more from preserved low-frequency binaural cues than from greater SNR improvement, whereas for smaller BILDs the opposite was true. Audiometric asymmetry reduced the influence of binaural hearing. In spatially diffuse noise, the maximal SNR improvement was generally beneficial. N 0 S π detection performance at 500 Hz predicted the benefit from low-frequency binaural cues. Together, these findings provide a basis for adapting bilateral directional processing to individual and situational influences. Further research is needed to investigate their generalizability to more realistic HA conditions (e.g., with low-frequency vent-transmitted sound). Copyright © 2017 Elsevier B.V. All rights reserved.

Representation of dynamic interaural phase difference in auditory cortex of awake rhesus macaques.

Science.gov (United States)

Scott, Brian H; Malone, Brian J; Semple, Malcolm N

2009-04-01

Neurons in auditory cortex of awake primates are selective for the spatial location of a sound source, yet the neural representation of the binaural cues that underlie this tuning remains undefined. We examined this representation in 283 single neurons across the low-frequency auditory core in alert macaques, trained to discriminate binaural cues for sound azimuth. In response to binaural beat stimuli, which mimic acoustic motion by modulating the relative phase of a tone at the two ears, these neurons robustly modulate their discharge rate in response to this directional cue. In accordance with prior studies, the preferred interaural phase difference (IPD) of these neurons typically corresponds to azimuthal locations contralateral to the recorded hemisphere. Whereas binaural beats evoke only transient discharges in anesthetized cortex, neurons in awake cortex respond throughout the IPD cycle. In this regard, responses are consistent with observations at earlier stations of the auditory pathway. Discharge rate is a band-pass function of the frequency of IPD modulation in most neurons (73%), but both discharge rate and temporal synchrony are independent of the direction of phase modulation. When subjected to a receiver operator characteristic analysis, the responses of individual neurons are insufficient to account for the perceptual acuity of these macaques in an IPD discrimination task, suggesting the need for neural pooling at the cortical level.

Frequency-Shift Detectors Bind Binaural as Well as Monaural Frequency Representations

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Carcagno, Samuele; Semal, Catherine; Demany, Laurent

2011-01-01

Previous psychophysical work provided evidence for the existence of automatic frequency-shift detectors (FSDs) that establish perceptual links between successive sounds. In this study, we investigated the characteristics of the FSDs with respect to the binaural system. Listeners were presented with sound sequences consisting of a chord of pure…

Efficient coding of spectrotemporal binaural sounds leads to emergence of the auditory space representation

Science.gov (United States)

Młynarski, Wiktor

2014-01-01

To date a number of studies have shown that receptive field shapes of early sensory neurons can be reproduced by optimizing coding efficiency of natural stimulus ensembles. A still unresolved question is whether the efficient coding hypothesis explains formation of neurons which explicitly represent environmental features of different functional importance. This paper proposes that the spatial selectivity of higher auditory neurons emerges as a direct consequence of learning efficient codes for natural binaural sounds. Firstly, it is demonstrated that a linear efficient coding transform—Independent Component Analysis (ICA) trained on spectrograms of naturalistic simulated binaural sounds extracts spatial information present in the signal. A simple hierarchical ICA extension allowing for decoding of sound position is proposed. Furthermore, it is shown that units revealing spatial selectivity can be learned from a binaural recording of a natural auditory scene. In both cases a relatively small subpopulation of learned spectrogram features suffices to perform accurate sound localization. Representation of the auditory space is therefore learned in a purely unsupervised way by maximizing the coding efficiency and without any task-specific constraints. This results imply that efficient coding is a useful strategy for learning structures which allow for making behaviorally vital inferences about the environment. PMID:24639644

Efficient coding of spectrotemporal binaural sounds leads to emergence of the auditory space representation

Directory of Open Access Journals (Sweden)

Wiktor eMlynarski

2014-03-01

Full Text Available To date a number of studies have shown that receptive field shapes of early sensory neurons can be reproduced by optimizing coding efficiency of natural stimulus ensembles. A still unresolved question is whether the efficientcoding hypothesis explains formation of neurons which explicitly represent environmental features of different functional importance. This paper proposes that the spatial selectivity of higher auditory neurons emerges as a direct consequence of learning efficient codes for natural binaural sounds. Firstly, it is demonstrated that a linear efficient coding transform - Independent Component Analysis (ICA trained on spectrograms of naturalistic simulated binaural sounds extracts spatial information present in the signal. A simple hierarchical ICA extension allowing for decoding of sound position is proposed. Furthermore, it is shown that units revealing spatial selectivity can be learned from a binaural recording of a natural auditory scene. In both cases a relatively small subpopulation of learned spectrogram features suffices to perform accurate sound localization. Representation of the auditory space is therefore learned in a purely unsupervised way by maximizing the coding efficiency and without any task-specific constraints. This results imply that efficient coding is a useful strategy for learning structures which allow for making behaviorally vital inferences about the environment.

Benefits to Speech Perception in Noise From the Binaural Integration of Electric and Acoustic Signals in Simulated Unilateral Deafness.

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Ma, Ning; Morris, Saffron; Kitterick, Pádraig Thomas

2016-01-01

This study used vocoder simulations with normal-hearing (NH) listeners to (1) measure their ability to integrate speech information from an NH ear and a simulated cochlear implant (CI), and (2) investigate whether binaural integration is disrupted by a mismatch in the delivery of spectral information between the ears arising from a misalignment in the mapping of frequency to place. Eight NH volunteers participated in the study and listened to sentences embedded in background noise via headphones. Stimuli presented to the left ear were unprocessed. Stimuli presented to the right ear (referred to as the CI-simulation ear) were processed using an eight-channel noise vocoder with one of the three processing strategies. An Ideal strategy simulated a frequency-to-place map across all channels that matched the delivery of spectral information between the ears. A Realistic strategy created a misalignment in the mapping of frequency to place in the CI-simulation ear where the size of the mismatch between the ears varied across channels. Finally, a Shifted strategy imposed a similar degree of misalignment in all channels, resulting in consistent mismatch between the ears across frequency. The ability to report key words in sentences was assessed under monaural and binaural listening conditions and at signal to noise ratios (SNRs) established by estimating speech-reception thresholds in each ear alone. The SNRs ensured that the monaural performance of the left ear never exceeded that of the CI-simulation ear. The advantages of binaural integration were calculated by comparing binaural performance with monaural performance using the CI-simulation ear alone. Thus, these advantages reflected the additional use of the experimentally constrained left ear and were not attributable to better-ear listening. Binaural performance was as accurate as, or more accurate than, monaural performance with the CI-simulation ear alone. When both ears supported a similar level of monaural

Monaural and binaural benefit from early reflections for speech intelligibility

DEFF Research Database (Denmark)

Arweiler, Iris; Buchholz, Jörg; Dau, Torsten

2010-01-01

The auditory system takes advantage of early reflections (ER’s) in a room by integrating them with the direct sound (DS) and thereby increasing the effective speech level. The energy, spectral content and direction of the ER’s are dependent on wall absorptions and room geometries and therefore di...... to investigate if ER processing is a monaural or binaural effect....

Noise reduction in binaural hearing aids : Analyzing the benefit over monaural systems

NARCIS (Netherlands)

Srinivasan, S.

2008-01-01

Binaural beamforming using signals from both left and right hearing aids offers greater potential for noise reduction than using signals from a single aid. However, wireless transmission of data imposes power constraints. Since most modern hearing aids have multiple microphones and are capable of

Detection and identification of monaural and binaural pitch contours in dyslexic listeners

DEFF Research Database (Denmark)

Santurette, Sébastien; Poelmans, Hanne; Luts, Heleen

2010-01-01

of dyslexic listeners to Huggins' pitch (HP). The present study clarified whether impaired binaural pitch perception is found in dyslexia. Results from a pitch contour identification test, performed in 31 dyslexic listeners and 31 matched controls, clearly showed that dyslexics perceived HP as well...

The effect of music with and without binaural beat audio on operative anxiety in patients undergoing cataract surgery: a randomized controlled trial

Science.gov (United States)

Wiwatwongwana, D; Vichitvejpaisal, P; Thaikruea, L; Klaphajone, J; Tantong, A; Wiwatwongwana, A

2016-01-01

Purpose To investigate the anxiolytic effects of binaural beat embedded audio in patients undergoing cataract surgery under local anesthesia. Methods This prospective RCT included 141 patients undergoing cataract surgery under local anesthesia. The patients were randomized into three groups; the Binaural beat music group (BB), the plain music intervention group (MI), and a control group (ear phones with no music). Blood pressure (BP) and heart rate were measured on admission, at the beginning of and 20 min after the start of the operation. Peri-operative anxiety level was assessed using the State-Trait Anxiety Inventory questionnaire (STAI). Results The BB and MI groups comprised 44 patients each and the control group 47. Patients in the MI group and BB group showed significant reduction of STAI state scores after music intervention compared with the control group (Pbinaural beat, was proven to decrease anxiety level and lower systolic BP. Patients who received binaural beat audio showed additional decrease in heart rate. Binaural beat embedded musical intervention may have benefit over musical intervention alone in decreasing operative anxiety. PMID:27740618

A Binaural CI Research Platform for Oticon Medical SP/XP Implants Enabling ITD/ILD and Variable Rate Processing

Science.gov (United States)

Adiloğlu, K.; Herzke, T.

2015-01-01

We present the first portable, binaural, real-time research platform compatible with Oticon Medical SP and XP generation cochlear implants. The platform consists of (a) a pair of behind-the-ear devices, each containing front and rear calibrated microphones, (b) a four-channel USB analog-to-digital converter, (c) real-time PC-based sound processing software called the Master Hearing Aid, and (d) USB-connected hardware and output coils capable of driving two implants simultaneously. The platform is capable of processing signals from the four microphones simultaneously and producing synchronized binaural cochlear implant outputs that drive two (bilaterally implanted) SP or XP implants. Both audio signal preprocessing algorithms (such as binaural beamforming) and novel binaural stimulation strategies (within the implant limitations) can be programmed by researchers. When the whole research platform is combined with Oticon Medical SP implants, interaural electrode timing can be controlled on individual electrodes to within ±1 µs and interaural electrode energy differences can be controlled to within ±2%. Hence, this new platform is particularly well suited to performing experiments related to interaural time differences in combination with interaural level differences in real-time. The platform also supports instantaneously variable stimulation rates and thereby enables investigations such as the effect of changing the stimulation rate on pitch perception. Because the processing can be changed on the fly, researchers can use this platform to study perceptual changes resulting from different processing strategies acutely. PMID:26721923

A Binaural CI Research Platform for Oticon Medical SP/XP Implants Enabling ITD/ILD and Variable Rate Processing.

Science.gov (United States)

Backus, B; Adiloğlu, K; Herzke, T

2015-12-30

We present the first portable, binaural, real-time research platform compatible with Oticon Medical SP and XP generation cochlear implants. The platform consists of (a) a pair of behind-the-ear devices, each containing front and rear calibrated microphones, (b) a four-channel USB analog-to-digital converter, (c) real-time PC-based sound processing software called the Master Hearing Aid, and (d) USB-connected hardware and output coils capable of driving two implants simultaneously. The platform is capable of processing signals from the four microphones simultaneously and producing synchronized binaural cochlear implant outputs that drive two (bilaterally implanted) SP or XP implants. Both audio signal preprocessing algorithms (such as binaural beamforming) and novel binaural stimulation strategies (within the implant limitations) can be programmed by researchers. When the whole research platform is combined with Oticon Medical SP implants, interaural electrode timing can be controlled on individual electrodes to within ±1 µs and interaural electrode energy differences can be controlled to within ±2%. Hence, this new platform is particularly well suited to performing experiments related to interaural time differences in combination with interaural level differences in real-time. The platform also supports instantaneously variable stimulation rates and thereby enables investigations such as the effect of changing the stimulation rate on pitch perception. Because the processing can be changed on the fly, researchers can use this platform to study perceptual changes resulting from different processing strategies acutely. © The Author(s) 2015.

Aging effects on the binaural interaction component of the auditory brainstem response in the Mongolian gerbil: Effects of interaural time and level differences.

Science.gov (United States)

Laumen, Geneviève; Tollin, Daniel J; Beutelmann, Rainer; Klump, Georg M

2016-07-01

The effect of interaural time difference (ITD) and interaural level difference (ILD) on wave 4 of the binaural and summed monaural auditory brainstem responses (ABRs) as well as on the DN1 component of the binaural interaction component (BIC) of the ABR in young and old Mongolian gerbils (Meriones unguiculatus) was investigated. Measurements were made at a fixed sound pressure level (SPL) and a fixed level above visually detected ABR threshold to compensate for individual hearing threshold differences. In both stimulation modes (fixed SPL and fixed level above visually detected ABR threshold) an effect of ITD on the latency and the amplitude of wave 4 as well as of the BIC was observed. With increasing absolute ITD values BIC latencies were increased and amplitudes were decreased. ILD had a much smaller effect on these measures. Old animals showed a reduced amplitude of the DN1 component. This difference was due to a smaller wave 4 in the summed monaural ABRs of old animals compared to young animals whereas wave 4 in the binaural-evoked ABR showed no age-related difference. In old animals the small amplitude of the DN1 component was correlated with small binaural-evoked wave 1 and wave 3 amplitudes. This suggests that the reduced peripheral input affects central binaural processing which is reflected in the BIC. Copyright © 2016 Elsevier B.V. All rights reserved.

Binaural interaction in low-frequency neurons in inferior colliculus of the cat. II. Effects of changing rate and direction of interaural phase.

Science.gov (United States)

Yin, T C; Kuwada, S

1983-10-01

We used the binaural beat stimulus to study the interaural phase sensitivity of inferior colliculus (IC) neurons in the cat. The binaural beat, produced by delivering tones of slightly different frequencies to the two ears, generates continuous and graded changes in interaural phase. Over 90% of the cells that exhibit a sensitivity to changes in the interaural delay also show a sensitivity to interaural phase disparities with the binaural beat. Cells respond with a burst of impulses with each complete cycle of the beat frequency. The period histogram obtained by binning the poststimulus time histogram on the beat frequency gives a measure of the interaural phase sensitivity of the cell. In general, there is good correspondence in the shapes of the period histograms generated from binaural beats and the interaural phase curves derived from interaural delays and in the mean interaural phase angle calculated from them. The magnitude of the beat frequency determines the rate of change of interaural phase and the sign determines the direction of phase change. While most cells respond in a phase-locked manner up to beat frequencies of 10 Hz, there are some cells tht will phase lock up to 80 Hz. Beat frequency and mean interaural phase angle are linearly related for most cells. Most cells respond equally in the two directions of phase change and with different rates of change, at least up to 10 Hz. However, some IC cells exhibit marked sensitivity to the speed of phase change, either responding more vigorously at low beat frequencies or at high beat frequencies. In addition, other cells demonstrate a clear directional sensitivity. The cells that show sensitivity to the direction and speed of phase changes would be expected to demonstrate a sensitivity to moving sound sources in the free field. Changes in the mean interaural phase of the binaural beat period histograms are used to determine the effects of changes in average and interaural intensity on the phase sensitivity

Directional loudness in an anechoic sound field, head-related transfer functions, and binaural summation

DEFF Research Database (Denmark)

Sivonen, Ville Pekka; Ellermeier, Wolfgang

2006-01-01

planes. Matches were obtained via a two-interval, adaptive forced-choice (2AFC) procedure for three center frequencies (0.4, 1 and 5 kHz) and two overall levels (45 and 65 dB SPL). The results showed that loudness is not constant over sound incidence angles, with directional sensitivity varying over......The effect of sound incidence angle on loudness was investigated using real sound sources positioned in an anechoic chamber. Eight normal-hearing listeners produced loudness matches between a frontal reference location and seven sources placed at other directions, both in the horizontal and median...... a range of up to 10 dB, exhibiting considerable frequency dependence, but only minor effects of overall level. The pattern of results varied substantially between subjects, but was largely accounted for by variations in individual head-related transfer functions. Modeling of binaural loudness based...

The effect of multimicrophone noise reduction systems on sound source localization by users of binaural hearing aids.

Science.gov (United States)

Van den Bogaert, Tim; Doclo, Simon; Wouters, Jan; Moonen, Marc

2008-07-01

This paper evaluates the influence of three multimicrophone noise reduction algorithms on the ability to localize sound sources. Two recently developed noise reduction techniques for binaural hearing aids were evaluated, namely, the binaural multichannel Wiener filter (MWF) and the binaural multichannel Wiener filter with partial noise estimate (MWF-N), together with a dual-monaural adaptive directional microphone (ADM), which is a widely used noise reduction approach in commercial hearing aids. The influence of the different algorithms on perceived sound source localization and their noise reduction performance was evaluated. It is shown that noise reduction algorithms can have a large influence on localization and that (a) the ADM only preserves localization in the forward direction over azimuths where limited or no noise reduction is obtained; (b) the MWF preserves localization of the target speech component but may distort localization of the noise component. The latter is dependent on signal-to-noise ratio and masking effects; (c) the MWF-N enables correct localization of both the speech and the noise components; (d) the statistical Wiener filter approach introduces a better combination of sound source localization and noise reduction performance than the ADM approach.

A Sparsity-Based Approach to 3D Binaural Sound Synthesis Using Time-Frequency Array Processing

Science.gov (United States)

Cobos, Maximo; Lopez, JoseJ; Spors, Sascha

2010-12-01

Localization of sounds in physical space plays a very important role in multiple audio-related disciplines, such as music, telecommunications, and audiovisual productions. Binaural recording is the most commonly used method to provide an immersive sound experience by means of headphone reproduction. However, it requires a very specific recording setup using high-fidelity microphones mounted in a dummy head. In this paper, we present a novel processing framework for binaural sound recording and reproduction that avoids the use of dummy heads, which is specially suitable for immersive teleconferencing applications. The method is based on a time-frequency analysis of the spatial properties of the sound picked up by a simple tetrahedral microphone array, assuming source sparseness. The experiments carried out using simulations and a real-time prototype confirm the validity of the proposed approach.

Alteration of frequency range for binaural beats in acute low-tone hearing loss.

Science.gov (United States)

Karino, Shotaro; Yamasoba, Tatsuya; Ito, Ken; Kaga, Kimitaka

2005-01-01

The effect of acute low-tone sensorineural hearing loss (ALHL) on the interaural frequency difference (IFD) required for perception of binaural beats (BBs) was investigated in 12 patients with unilateral ALHL and 7 patients in whom ALHL had lessened. A continuous pure tone of 30 dB sensation level at 250 Hz was presented to the contralateral, normal-hearing ear. The presence of BBs was determined by a subjective yes-no procedure as the frequency of a loudness-balanced test tone was gradually adjusted around 250 Hz in the affected ear. The frequency range in which no BBs were perceived (FRNB) was significantly wider in the patients with ALHL than in the controls, and FRNBs became narrower in the recovered ALHL group. Specifically, detection of slow BBs with a small IFD was impaired in this limited (10 s) observation period. The significant correlation between the hearing level at 250 Hz and FRNBs suggests that FRNBs represent the degree of cochlear damage caused by ALHL.

AN INVESTIGATION OF DIFFERENTIAL BINAURAL STIMULATION IN THE TEACHING OF A FOREIGN LANGUAGE.

Science.gov (United States)

VAN RIPER, CHARLES

THIS STUDY DETERMINED WHETHER OR NOT DIFFERENTIAL BINAURAL STIMULATIONS CAN BE USED EFFECTIVELY TO IMPROVE PRONUNCIATION IN FOREIGN LANGUAGE TEACHING. THE OBJECTIVE WAS TO DETERMINE WHAT EFFECT HEARING SIMULTANEOUSLY THE TEACHER'S VOICE IN ONE EAR AND HIS OWN VOICE IN THE OTHER WOULD HAVE ON A STUDENT'S ABILITY TO COMPARE THE DIFFERENCES IN…

ROBUST LOCALISATION OF MULTIPLE SPEAKERS EXPLOITING HEAD MOVEMENTS AND MULTI-CONDITIONAL TRAINING OF BINAURAL CUES

DEFF Research Database (Denmark)

May, Tobias; Ma, Ning; Brown, Guy

2015-01-01

differences (ITDs) and interaural level dif- ferences (ILDs) in the front and rear hemifield, a machine hearing system is presented which combines supervised learning of binaural cues using multi-conditional training (MCT) with a head movement strategy. A systematic evaluation showed that this approach...

Techniques and applications for binaural sound manipulation in human-machine interfaces

Science.gov (United States)

Begault, Durand R.; Wenzel, Elizabeth M.

1992-01-01

The implementation of binaural sound to speech and auditory sound cues (auditory icons) is addressed from both an applications and technical standpoint. Techniques overviewed include processing by means of filtering with head-related transfer functions. Application to advanced cockpit human interface systems is discussed, although the techniques are extendable to any human-machine interface. Research issues pertaining to three-dimensional sound displays under investigation at the Aerospace Human Factors Division at NASA Ames Research Center are described.

Modulatory Effect of Association of Brain Stimulation by Light and Binaural Beats in Specific Brain Waves.

Science.gov (United States)

Calomeni, Mauricio Rocha; Furtado da Silva, Vernon; Velasques, Bruna Brandão; Feijó, Olavo Guimarães; Bittencourt, Juliana Marques; Ribeiro de Souza E Silva, Alair Pedro

2017-01-01

One of the positive effects of brain stimulation is interhemispheric modulation as shown in some scientific studies. This study examined if a type of noninvasive stimulation using binaural beats with led-lights and sound would show different modulatory effects upon Alfa and SMR brain waves of elderlies and children with some disease types. The sample included 75 individuals of both genders, being, randomly, divided in 6 groups. Groups were named elderly without dementia diagnosis (EWD), n=15, 76±8 years, elderly diagnosed with Parkinson's disease (EDP), n=15, 72±7 years, elderly diagnosed with Alzheimer's disease (EDA), n=15, 81±6 years. The other groups were named children with Autism (CA), n=10, 11±4 years, children with Intellectual Impairment (CII), n=10, 12 ±5 years and children with normal cognitive development (CND), n=10, 11±4 years. Instruments were the Mini Mental State Examination Test (MMSE), EEG-Neurocomputer instrument for brain waves registration, brain stimulator, Digit Span Test and a Protocol for working memory training. Data collection followed a pre and post-conjugated stimulation version. The results of the inferential statistics showed that the stimulation protocol had different effects on Alpha and SMR brain waves of the patients. Also, indicated gains in memory functions, for both, children and elderlies as related to gains in brain waves modulation. The results may receive and provide support to a range of studies examining brain modulation and synaptic plasticity. Also, it was emphasized in the results discussion that there was the possibility of the technique serving as an accessory instrument to alternative brain therapies.

Emphasis of spatial cues in the temporal fine structure during the rising segments of amplitude-modulated sounds II: single-neuron recordings

Science.gov (United States)

Marquardt, Torsten; Stange, Annette; Pecka, Michael; Grothe, Benedikt; McAlpine, David

2014-01-01

Recently, with the use of an amplitude-modulated binaural beat (AMBB), in which sound amplitude and interaural-phase difference (IPD) were modulated with a fixed mutual relationship (Dietz et al. 2013b), we demonstrated that the human auditory system uses interaural timing differences in the temporal fine structure of modulated sounds only during the rising portion of each modulation cycle. However, the degree to which peripheral or central mechanisms contribute to the observed strong dominance of the rising slope remains to be determined. Here, by recording responses of single neurons in the medial superior olive (MSO) of anesthetized gerbils and in the inferior colliculus (IC) of anesthetized guinea pigs to AMBBs, we report a correlation between the position within the amplitude-modulation (AM) cycle generating the maximum response rate and the position at which the instantaneous IPD dominates the total neural response. The IPD during the rising segment dominates the total response in 78% of MSO neurons and 69% of IC neurons, with responses of the remaining neurons predominantly coding the IPD around the modulation maximum. The observed diversity of dominance regions within the AM cycle, especially in the IC, and its comparison with the human behavioral data suggest that only the subpopulation of neurons with rising slope dominance codes the sound-source location in complex listening conditions. A comparison of two models to account for the data suggests that emphasis on IPDs during the rising slope of the AM cycle depends on adaptation processes occurring before binaural interaction. PMID:24554782

Intelligibility for Binaural Speech with Discarded Low-SNR Speech Components.

Science.gov (United States)

Schoenmaker, Esther; van de Par, Steven

2016-01-01

Speech intelligibility in multitalker settings improves when the target speaker is spatially separated from the interfering speakers. A factor that may contribute to this improvement is the improved detectability of target-speech components due to binaural interaction in analogy to the Binaural Masking Level Difference (BMLD). This would allow listeners to hear target speech components within specific time-frequency intervals that have a negative SNR, similar to the improvement in the detectability of a tone in noise when these contain disparate interaural difference cues. To investigate whether these negative-SNR target-speech components indeed contribute to speech intelligibility, a stimulus manipulation was performed where all target components were removed when local SNRs were smaller than a certain criterion value. It can be expected that for sufficiently high criterion values target speech components will be removed that do contribute to speech intelligibility. For spatially separated speakers, assuming that a BMLD-like detection advantage contributes to intelligibility, degradation in intelligibility is expected already at criterion values below 0 dB SNR. However, for collocated speakers it is expected that higher criterion values can be applied without impairing speech intelligibility. Results show that degradation of intelligibility for separated speakers is only seen for criterion values of 0 dB and above, indicating a negligible contribution of a BMLD-like detection advantage in multitalker settings. These results show that the spatial benefit is related to a spatial separation of speech components at positive local SNRs rather than to a BMLD-like detection improvement for speech components at negative local SNRs.

An Alternative Method to Compute the Bit Error Probability of Modulation Schemes Subject to Nakagami- Fading

Directory of Open Access Journals (Sweden)

Madeiro Francisco

2010-01-01

Full Text Available Abstract This paper presents an alternative method for determining exact expressions for the bit error probability (BEP of modulation schemes subject to Nakagami- fading. In this method, the Nakagami- fading channel is seen as an additive noise channel whose noise is modeled as the ratio between Gaussian and Nakagami- random variables. The method consists of using the cumulative density function of the resulting noise to obtain closed-form expressions for the BEP of modulation schemes subject to Nakagami- fading. In particular, the proposed method is used to obtain closed-form expressions for the BEP of -ary quadrature amplitude modulation ( -QAM, -ary pulse amplitude modulation ( -PAM, and rectangular quadrature amplitude modulation ( -QAM under Nakagami- fading. The main contribution of this paper is to show that this alternative method can be used to reduce the computational complexity for detecting signals in the presence of fading.

Pilot feasibility study of binaural auditory beats for reducing symptoms of inattention in children and adolescents with attention-deficit/hyperactivity disorder.

Science.gov (United States)

Kennel, Susan; Taylor, Ann Gill; Lyon, Debra; Bourguignon, Cheryl

2010-02-01

The purpose of this pilot study was to explore the potential for the use of binaural auditory beat stimulation to reduce the symptom of inattention in children and adolescents with attention-deficit/hyperactivity disorder. This pilot study had a randomized, double-blind, placebo-controlled design. Twenty participants were randomly assigned to listen to either an audio program on compact disk that contained binaural auditory beats or a sham audio program that did not have binaural beats for 20 minutes, three times a week for 3 weeks. The Children's Color Trails Test, the Color Trails Test, the Test of Variables of Attention (TOVA), and the Homework Problem Checklist were used to measure changes in inattention pre- and postintervention. Repeated measures analysis of variance was used to analyze pre- and postintervention scores on the Color Trails Tests, Homework Problem Checklist, and the TOVA. The effect of time was significant on the Color Trails Test. However, there were no significant group differences on the Color Trails Test or the TOVA scores postintervention. Parents reported that the study participants had fewer homework problems postintervention. The results from this study indicate that binaural auditory beat stimulation did not significantly reduce the symptom of inattention in the experimental group. However, parents and adolescents stated that homework problems due to inattention improved during the 3-week study. Parents and participants stated that the modality was easy to use and helpful. Therefore, this modality should be studied over a longer time frame in a larger sample to further its effectiveness to reduce the symptom of inattention in those diagnosed with attention-deficit/hyperactivity disorder. Copyright 2010 Elsevier Inc. All rights reserved.

Eliminating the Attentional Blink through Binaural Beats: A Case for Tailored Cognitive Enhancement

OpenAIRE

Reedijk, Susan A.; Bolders, Anne; Colzato, Lorenza S.; Hommel, Bernhard

2015-01-01

Enhancing human cognitive performance is a topic that continues to spark scientific interest. Studies into cognitive-enhancement techniques often fail to take inter-individual differences into account, however, which leads to underestimation of the effectiveness of these techniques. The current study investigated the effect of binaural beats, a cognitive-enhancement technique, on attentional control in an attentional blink (AB) task. As predicted from a neurocognitive approach to cognitive co...

The effects of noise-bandwidth, noise-fringe duration, and temporal signal location on the binaural masking-level difference.

Science.gov (United States)

Yasin, Ifat; Henning, G Bruce

2012-07-01

The effects of forward and backward noise fringes on binaural signal detectability were investigated. Masked thresholds for a 12-ms, 250-Hz, sinusoidal signal masked by Gaussian noise, centered at 250 Hz, with bandwidths from 3 to 201 Hz, were obtained in N(0)S(0) and N(0)S(π) configurations. The signal was (a) temporally centered in a 12-ms noise burst (no fringe), (b) presented at the start of a 600-ms noise burst (backward fringe), or (c) temporally centered in a 600-ms noise burst (forward-plus-backward fringe). For noise bandwidths between 3 and 75 Hz, detection in N(0)S(0) improved with the addition of a backward fringe, improving further with an additional forward fringe; there was little improvement in N(0)S(π). The binaural masking-level difference (BMLD) increased from 0 to 8 dB with a forward-plus-backward fringe as noise bandwidths increased to 100 Hz, increasing slightly to 10 dB at 201 Hz. This two-stage increase was less pronounced with a backward fringe. With no fringe, the BMLD was about 10-14 dB at all bandwidths. Performance appears to result from the interaction of across-time and across-frequency listening strategies and the possible effects of gain reduction and suppression, which combine in complex ways. Current binaural models are, as yet, unable to account fully for these effects.

Analysis of EEG activity in response to binaural beats with different frequencies.

Science.gov (United States)

Gao, Xiang; Cao, Hongbao; Ming, Dong; Qi, Hongzhi; Wang, Xuemin; Wang, Xiaolu; Chen, Runge; Zhou, Peng

2014-12-01

When two coherent sounds with nearly similar frequencies are presented to each ear respectively with stereo headphones, the brain integrates the two signals and produces a sensation of a third sound called binaural beat (BB). Although earlier studies showed that BB could influence behavior and cognition, common agreement on the mechanism of BB has not been reached yet. In this work, we employed Relative Power (RP), Phase Locking Value (PLV) and Cross-Mutual Information (CMI) to track EEG changes during BB stimulations. EEG signals were acquired from 13 healthy subjects. Five-minute BBs with four different frequencies were tested: delta band (1 Hz), theta band (5 Hz), alpha band (10 Hz) and beta band (20 Hz). We observed RP increase in theta and alpha bands and decrease in beta band during delta and alpha BB stimulations. RP decreased in beta band during theta BB, while RP decreased in theta band during beta BB. However, no clear brainwave entrainment effect was identified. Connectivity changes were detected following the variation of RP during BB stimulations. Our observation supports the hypothesis that BBs could affect functional brain connectivity, suggesting that the mechanism of BB-brain interaction is worth further study. Copyright © 2014. Published by Elsevier B.V.

Hearing in alpacas (Vicugna pacos): audiogram, localization acuity, and use of binaural locus cues.

Science.gov (United States)

Heffner, Rickye S; Koay, Gimseong; Heffner, Henry E

2014-02-01

Behavioral audiograms and sound localization abilities were determined for three alpacas (Vicugna pacos). Their hearing at a level of 60 dB sound pressure level (SPL) (re 20 μPa) extended from 40 Hz to 32.8 kHz, a range of 9.7 octaves. They were most sensitive at 8 kHz, with an average threshold of -0.5 dB SPL. The minimum audible angle around the midline for 100-ms broadband noise was 23°, indicating relatively poor localization acuity and potentially supporting the finding that animals with broad areas of best vision have poorer sound localization acuity. The alpacas were able to localize low-frequency pure tones, indicating that they can use the binaural phase cue, but they were unable to localize pure tones above the frequency of phase ambiguity, thus indicating complete inability to use the binaural intensity-difference cue. In contrast, the alpacas relied on their high-frequency hearing for pinna cues; they could discriminate front-back sound sources using 3-kHz high-pass noise, but not 3-kHz low-pass noise. These results are compared to those of other hoofed mammals and to mammals more generally.

Robust speech dereverberation with a neural network-based post-filter that exploits multi-conditional training of binaural cues

DEFF Research Database (Denmark)

May, Tobias

2018-01-01

-frequency (T-F) units. A multi-conditional training (MCT) procedure was used to simulate the uncertainties of short-term binaural cues in response to room reverberation by mixing the direct part of head related impulse responses (HRIRs) with diffuse noise. Despite being trained with only anechoic HRIRs...

Electrophysiological and psychophysical asymmetries in sensitivity to interaural correlation gaps and implications for binaural integration time.

Science.gov (United States)

Lüddemann, Helge; Kollmeier, Birger; Riedel, Helmut

2016-02-01

Brief deviations of interaural correlation (IAC) can provide valuable cues for detection, segregation and localization of acoustic signals. This study investigated the processing of such "binaural gaps" in continuously running noise (100-2000 Hz), in comparison to silent "monaural gaps", by measuring late auditory evoked potentials (LAEPs) and perceptual thresholds with novel, iteratively optimized stimuli. Mean perceptual binaural gap duration thresholds exhibited a major asymmetry: they were substantially shorter for uncorrelated gaps in correlated and anticorrelated reference noise (1.75 ms and 4.1 ms) than for correlated and anticorrelated gaps in uncorrelated reference noise (26.5 ms and 39.0 ms). The thresholds also showed a minor asymmetry: they were shorter in the positive than in the negative IAC range. The mean behavioral threshold for monaural gaps was 5.5 ms. For all five gap types, the amplitude of LAEP components N1 and P2 increased linearly with the logarithm of gap duration. While perceptual and electrophysiological thresholds matched for monaural gaps, LAEP thresholds were about twice as long as perceptual thresholds for uncorrelated gaps, but half as long for correlated and anticorrelated gaps. Nevertheless, LAEP thresholds showed the same asymmetries as perceptual thresholds. For gap durations below 30 ms, LAEPs were dominated by the processing of the leading edge of a gap. For longer gap durations, in contrast, both the leading and the lagging edge of a gap contributed to the evoked response. Formulae for the equivalent rectangular duration (ERD) of the binaural system's temporal window were derived for three common window shapes. The psychophysical ERD was 68 ms for diotic and about 40 ms for anti- and uncorrelated noise. After a nonlinear Z-transform of the stimulus IAC prior to temporal integration, ERDs were about 10 ms for reference correlations of ±1 and 80 ms for uncorrelated reference. Hence, a physiologically motivated

Objective Prediction of Hearing Aid Benefit Across Listener Groups Using Machine Learning: Speech Recognition Performance With Binaural Noise-Reduction Algorithms.

Science.gov (United States)

Schädler, Marc R; Warzybok, Anna; Kollmeier, Birger

2018-01-01

The simulation framework for auditory discrimination experiments (FADE) was adopted and validated to predict the individual speech-in-noise recognition performance of listeners with normal and impaired hearing with and without a given hearing-aid algorithm. FADE uses a simple automatic speech recognizer (ASR) to estimate the lowest achievable speech reception thresholds (SRTs) from simulated speech recognition experiments in an objective way, independent from any empirical reference data. Empirical data from the literature were used to evaluate the model in terms of predicted SRTs and benefits in SRT with the German matrix sentence recognition test when using eight single- and multichannel binaural noise-reduction algorithms. To allow individual predictions of SRTs in binaural conditions, the model was extended with a simple better ear approach and individualized by taking audiograms into account. In a realistic binaural cafeteria condition, FADE explained about 90% of the variance of the empirical SRTs for a group of normal-hearing listeners and predicted the corresponding benefits with a root-mean-square prediction error of 0.6 dB. This highlights the potential of the approach for the objective assessment of benefits in SRT without prior knowledge about the empirical data. The predictions for the group of listeners with impaired hearing explained 75% of the empirical variance, while the individual predictions explained less than 25%. Possibly, additional individual factors should be considered for more accurate predictions with impaired hearing. A competing talker condition clearly showed one limitation of current ASR technology, as the empirical performance with SRTs lower than -20 dB could not be predicted.

Rapid Prototyping of an Electrically-Small Antenna for Binaural-Hearing Instruments

DEFF Research Database (Denmark)

Ruaro, Andrea; Thaysen, Jesper; Jakobsen, Kaj Bjarne

2015-01-01

Rapid prototyping is emerging as a technology that can provide detailed mechanical parts, e.g., for use in antenna mock-ups, in a short lead time. Nevertheless, one of the main issues associated with it is that the materials suitable for 3D printing are not characterized at radio frequencies (RF......). This study analyzes the main RF parameters (dielectric constant, loss tangent, surface roughness) and applies the results to the modeling of the prototype of an electrically small (ESA) antenna for binaural hearing instruments applications. After discussing the specific technology choices...... and their relevancies, it is shown how the analyzed parameters can be used to obtain good correlation between simulations and measurements....

Attentional modulation of auditory steady-state responses.

Science.gov (United States)

Mahajan, Yatin; Davis, Chris; Kim, Jeesun

2014-01-01

Auditory selective attention enables task-relevant auditory events to be enhanced and irrelevant ones suppressed. In the present study we used a frequency tagging paradigm to investigate the effects of attention on auditory steady state responses (ASSR). The ASSR was elicited by simultaneously presenting two different streams of white noise, amplitude modulated at either 16 and 23.5 Hz or 32.5 and 40 Hz. The two different frequencies were presented to each ear and participants were instructed to selectively attend to one ear or the other (confirmed by behavioral evidence). The results revealed that modulation of ASSR by selective attention depended on the modulation frequencies used and whether the activation was contralateral or ipsilateral. Attention enhanced the ASSR for contralateral activation from either ear for 16 Hz and suppressed the ASSR for ipsilateral activation for 16 Hz and 23.5 Hz. For modulation frequencies of 32.5 or 40 Hz attention did not affect the ASSR. We propose that the pattern of enhancement and inhibition may be due to binaural suppressive effects on ipsilateral stimulation and the dominance of contralateral hemisphere during dichotic listening. In addition to the influence of cortical processing asymmetries, these results may also reflect a bias towards inhibitory ipsilateral and excitatory contralateral activation present at the level of inferior colliculus. That the effect of attention was clearest for the lower modulation frequencies suggests that such effects are likely mediated by cortical brain structures or by those in close proximity to cortex.

Neural signals of selective attention are modulated by subjective preferences and buying decisions in a virtual shopping task.

Science.gov (United States)

Goto, Nobuhiko; Mushtaq, Faisal; Shee, Dexter; Lim, Xue Li; Mortazavi, Matin; Watabe, Motoki; Schaefer, Alexandre

2017-09-01

We investigated whether well-known neural markers of selective attention to motivationally-relevant stimuli were modulated by variations in subjective preference towards consumer goods in a virtual shopping task. Specifically, participants viewed and rated pictures of various goods on the extent to which they wanted each item, which they could potentially purchase afterwards. Using the event-related potentials (ERP) method, we found that variations in subjective preferences for consumer goods strongly modulated positive slow waves (PSW) from 800 to 3000 milliseconds after stimulus onset. We also found that subjective preferences modulated the N200 and the late positive potential (LPP). In addition, we found that both PSW and LPP were modulated by subsequent buying decisions. Overall, these findings show that well-known brain event-related potentials reflecting selective attention processes can reliably index preferences to consumer goods in a shopping environment. Based on a large body of previous research, we suggest that early ERPs (e.g. the N200) to consumer goods could be indicative of preferences driven by unconditional and automatic processes, whereas later ERPs such as the LPP and the PSW could reflect preferences built upon more elaborative and conscious cognitive processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Objective Prediction of Hearing Aid Benefit Across Listener Groups Using Machine Learning: Speech Recognition Performance With Binaural Noise-Reduction Algorithms

Science.gov (United States)

Schädler, Marc R.; Warzybok, Anna; Kollmeier, Birger

2018-01-01

The simulation framework for auditory discrimination experiments (FADE) was adopted and validated to predict the individual speech-in-noise recognition performance of listeners with normal and impaired hearing with and without a given hearing-aid algorithm. FADE uses a simple automatic speech recognizer (ASR) to estimate the lowest achievable speech reception thresholds (SRTs) from simulated speech recognition experiments in an objective way, independent from any empirical reference data. Empirical data from the literature were used to evaluate the model in terms of predicted SRTs and benefits in SRT with the German matrix sentence recognition test when using eight single- and multichannel binaural noise-reduction algorithms. To allow individual predictions of SRTs in binaural conditions, the model was extended with a simple better ear approach and individualized by taking audiograms into account. In a realistic binaural cafeteria condition, FADE explained about 90% of the variance of the empirical SRTs for a group of normal-hearing listeners and predicted the corresponding benefits with a root-mean-square prediction error of 0.6 dB. This highlights the potential of the approach for the objective assessment of benefits in SRT without prior knowledge about the empirical data. The predictions for the group of listeners with impaired hearing explained 75% of the empirical variance, while the individual predictions explained less than 25%. Possibly, additional individual factors should be considered for more accurate predictions with impaired hearing. A competing talker condition clearly showed one limitation of current ASR technology, as the empirical performance with SRTs lower than −20 dB could not be predicted. PMID:29692200

Beamforming under Quantization Errors in Wireless Binaural Hearing Aids

Directory of Open Access Journals (Sweden)

Srinivasan Sriram

2008-01-01

Full Text Available Improving the intelligibility of speech in different environments is one of the main objectives of hearing aid signal processing algorithms. Hearing aids typically employ beamforming techniques using multiple microphones for this task. In this paper, we discuss a binaural beamforming scheme that uses signals from the hearing aids worn on both the left and right ears. Specifically, we analyze the effect of a low bit rate wireless communication link between the left and right hearing aids on the performance of the beamformer. The scheme is comprised of a generalized sidelobe canceller (GSC that has two inputs: observations from one ear, and quantized observations from the other ear, and whose output is an estimate of the desired signal. We analyze the performance of this scheme in the presence of a localized interferer as a function of the communication bit rate using the resultant mean-squared error as the signal distortion measure.

Beamforming under Quantization Errors in Wireless Binaural Hearing Aids

Directory of Open Access Journals (Sweden)

Kees Janse

2008-09-01

Full Text Available Improving the intelligibility of speech in different environments is one of the main objectives of hearing aid signal processing algorithms. Hearing aids typically employ beamforming techniques using multiple microphones for this task. In this paper, we discuss a binaural beamforming scheme that uses signals from the hearing aids worn on both the left and right ears. Specifically, we analyze the effect of a low bit rate wireless communication link between the left and right hearing aids on the performance of the beamformer. The scheme is comprised of a generalized sidelobe canceller (GSC that has two inputs: observations from one ear, and quantized observations from the other ear, and whose output is an estimate of the desired signal. We analyze the performance of this scheme in the presence of a localized interferer as a function of the communication bit rate using the resultant mean-squared error as the signal distortion measure.

Teaching Earth Sciences as an interdisciplinary subject: Novel module design involving research literature

Science.gov (United States)

Tong, Vincent C. H.

2010-05-01

The study of Earth Sciences requires an interdisciplinary approach as it involves understanding scientific knowledge originating from a wide spectrum of research areas. Not only does it include subjects ranging from, for instance, hydrogeology to deep crustal seismology and from climate science to oceanography, but it also has many direct applications in closely related disciplines such as environmental engineering and natural resources management. While research crossing traditional disciplinary boundaries in geosciences is becoming increasingly common, there is only limited integration of interdisciplinary research in the teaching of the subject. Given that the transition from undergraduate education based on subject modules to postgraduate interdisciplinary research is never easy, such integration is a highly desirable pedagogical approach at both undergraduate and postgraduate levels. My presentation is based on a recent teaching project involving novel design of an undergraduate course. The course is implemented in order to address the synergy between research and teaching (Tong, 2009). This project has been shown to be effective and successful in teaching geosciences undergraduates at the University of London. The module consists of studying core geophysical principles and linking them directly to a selection of recently published research papers in a wide range of interdisciplinary applications. Research reviewing and reporting techniques are systematically developed, practised and fully integrated into teaching of the core scientific theories. A fully-aligned assignment with a feedback website invites the students to reflect on the scientific knowledge and the study skills related to research literature they have acquired in the course. This teaching project has been recognized by a teaching award (http://www.clpd.bbk.ac.uk/staff/BETA). In this presentation, I will discuss how undergraduate teaching with a focus on research literature in Earth Sciences can

Frequency response areas in the inferior colliculus: nonlinearity and binaural interaction

Directory of Open Access Journals (Sweden)

Jane J Yu

2013-05-01

Full Text Available The tuning, binaural properties, and encoding characteristics of neurons in the central nucleus of the inferior colliculus (CNIC were investigated to shed light on nonlinearities in the responses of these neurons. Results were analyzed for three types of neurons (I, O, and V in the CNIC of decerebrate cats. Rate responses to binaural stimuli were characterized using a 1st- plus 2nd-order spectral integration model. Parameters of the model were derived using broadband stimuli with random spectral shapes (RSS. This method revealed four characteristics of CNIC neurons: (1 Tuning curves derived from broadband stimuli have fixed (i. e., level tolerant bandwidths across a 50-60 dB range of sound levels; (2 1st-order contralateral weights (particularly for type I and O neurons were usually larger in magnitude than corresponding ipsilateral weights; (3 contralateral weights were more important than ipsilateral weights when using the model to predict responses to untrained noise stimuli; and (4 2nd-order weight functions demonstrate frequency selectivity different from that of 1st-order weight functions. Furthermore, while the inclusion of 2nd-order terms in the model usually improved response predictions related to untrained RSS stimuli, they had limited impact on predictions related to other forms of filtered broadband noise (e. g., virtual space stimuli. The accuracy of the predictions varied considerably by response type. Predictions were most accurate for I neurons, and less accurate for O and V neurons, except at the lowest stimulus levels. These differences in prediction performance support the idea that type I, O, and V neurons encode different aspects of the stimulus: while type I neurons are most capable of producing linear representations of spectral shape, type O and V neurons may encode spectral features or temporal stimulus properties in a manner not easily explained with the low-order model. Supported by NIH grant DC00115.

Attentional Modulation of Auditory Steady-State Responses

Science.gov (United States)

Mahajan, Yatin; Davis, Chris; Kim, Jeesun

2014-01-01

Auditory selective attention enables task-relevant auditory events to be enhanced and irrelevant ones suppressed. In the present study we used a frequency tagging paradigm to investigate the effects of attention on auditory steady state responses (ASSR). The ASSR was elicited by simultaneously presenting two different streams of white noise, amplitude modulated at either 16 and 23.5 Hz or 32.5 and 40 Hz. The two different frequencies were presented to each ear and participants were instructed to selectively attend to one ear or the other (confirmed by behavioral evidence). The results revealed that modulation of ASSR by selective attention depended on the modulation frequencies used and whether the activation was contralateral or ipsilateral. Attention enhanced the ASSR for contralateral activation from either ear for 16 Hz and suppressed the ASSR for ipsilateral activation for 16 Hz and 23.5 Hz. For modulation frequencies of 32.5 or 40 Hz attention did not affect the ASSR. We propose that the pattern of enhancement and inhibition may be due to binaural suppressive effects on ipsilateral stimulation and the dominance of contralateral hemisphere during dichotic listening. In addition to the influence of cortical processing asymmetries, these results may also reflect a bias towards inhibitory ipsilateral and excitatory contralateral activation present at the level of inferior colliculus. That the effect of attention was clearest for the lower modulation frequencies suggests that such effects are likely mediated by cortical brain structures or by those in close proximity to cortex. PMID:25334021

Attentional modulation of auditory steady-state responses.

Directory of Open Access Journals (Sweden)

Yatin Mahajan

Full Text Available Auditory selective attention enables task-relevant auditory events to be enhanced and irrelevant ones suppressed. In the present study we used a frequency tagging paradigm to investigate the effects of attention on auditory steady state responses (ASSR. The ASSR was elicited by simultaneously presenting two different streams of white noise, amplitude modulated at either 16 and 23.5 Hz or 32.5 and 40 Hz. The two different frequencies were presented to each ear and participants were instructed to selectively attend to one ear or the other (confirmed by behavioral evidence. The results revealed that modulation of ASSR by selective attention depended on the modulation frequencies used and whether the activation was contralateral or ipsilateral. Attention enhanced the ASSR for contralateral activation from either ear for 16 Hz and suppressed the ASSR for ipsilateral activation for 16 Hz and 23.5 Hz. For modulation frequencies of 32.5 or 40 Hz attention did not affect the ASSR. We propose that the pattern of enhancement and inhibition may be due to binaural suppressive effects on ipsilateral stimulation and the dominance of contralateral hemisphere during dichotic listening. In addition to the influence of cortical processing asymmetries, these results may also reflect a bias towards inhibitory ipsilateral and excitatory contralateral activation present at the level of inferior colliculus. That the effect of attention was clearest for the lower modulation frequencies suggests that such effects are likely mediated by cortical brain structures or by those in close proximity to cortex.

Feasibity of Using a Measure of Heart Rate Change in Human Adults to Signal Occurrence of Tone

Science.gov (United States)

1977-11-01

clearly with the binaural subjects in the 85 dB free response live trials situation on post-tone offset beat 1. Here, the significant response...seen when comparing the sign test results of post-tone offset beat I in the binaural 15 db motor response live trial situation to the analagous 85 db...subject response consistency. Tills is most evident in the binaural 85 db fret live situation comparison of post-tone offset beat one to

Survey of Methods to Assess Workload

Science.gov (United States)

1979-08-01

thesis study which had to do with the effect of binaural beats upon performan:.e (2) found out there was a subjectively experienced quality of beats ...were forced to conclude that the neuralmechanism by which binaural beats influenced performance is not open to correct subjective evaluation. In terms of...methods for developing indicies of pilot workload, FAA Report (FAA-AN-77- 15), July 1977. 2. ,’ R. E. The effect of binaural beats on performance, J

Assessing the contribution of binaural cues for apparent source width perception via a functional model

DEFF Research Database (Denmark)

Käsbach, Johannes; Hahmann, Manuel; May, Tobias

2016-01-01

In echoic conditions, sound sources are not perceived as point sources but appear to be expanded. The expansion in the horizontal dimension is referred to as apparent source width (ASW). To elicit this perception, the auditory system has access to fluctuations of binaural cues, the interaural time...... a statistical representation of ITDs and ILDs based on percentiles integrated over time and frequency. The model’s performance was evaluated against psychoacoustic data obtained with noise, speech and music signals in loudspeakerbased experiments. A robust model prediction of ASW was achieved using a cross...

Subjective study of preferred listening conditions in Italian Catholic churches

Science.gov (United States)

Martellotta, Francesco

2008-10-01

The paper describes the results of research aimed at investigating the preferred subjective listening conditions inside churches. The effect of different musical motifs (spanning Gregorian chants to symphonic music) was investigated and regression analysis was performed in order to point out the relationship between subjective ratings and acoustical parameters. In order to present realistic listening conditions to the subjects a small subset of nine churches was selected among a larger set of acoustic data collected in several Italian churches during a widespread on-site survey. The subset represented different architectural styles and shapes, and was characterized by average listening conditions. For each church a single source-receiver combination with fixed relative positions was chosen. Measured binaural impulse responses were cross-talk cancelled and then convolved with five anechoic motifs. Paired comparisons were finally performed, asking a trained panel of subjects their preference. Factor analysis pointed out a substantially common underlying pattern characterizing subjective responses. The results show that preferred listening conditions vary as a function of the musical motif, depending on early decay time for choral music and on a combination of initial time delay and lateral energy for instrumental music.

Music Improves Subjective Feelings Leading to Cardiac Autonomic Nervous Modulation: A Pilot Study.

Science.gov (United States)

Kume, Satoshi; Nishimura, Yukako; Mizuno, Kei; Sakimoto, Nae; Hori, Hiroshi; Tamura, Yasuhisa; Yamato, Masanori; Mitsuhashi, Rika; Akiba, Keigo; Koizumi, Jun-Ichi; Watanabe, Yasuyoshi; Kataoka, Yosky

2017-01-01

It is widely accepted that listening to music improves subjective feelings and reduces fatigue sensations, and different kinds of music lead to different activations of these feelings. Recently, cardiac autonomic nervous modulation has been proposed as a useful objective indicator of fatigue. However, scientific considerations of the relation between feelings of fatigue and cardiac autonomic nervous modulation while listening to music are still lacking. In this study, we examined which subjective feelings of fatigue are related to participants' cardiac autonomic nervous function while they listen to music. We used an album of comfortable and relaxing environmental music, with blended sounds from a piano and violin as well as natural sound sources. We performed a crossover trial of environmental music and silent sessions for 20 healthy subjects, 12 females, and 8 males, after their daily work shift. We measured changes in eight types of subjective feelings, including healing, fatigue, sleepiness, relaxation, and refreshment, using the KOKORO scale, a subjective mood measurement system for self-reported feelings. Further, we obtained measures of cardiac autonomic nervous function on the basis of heart rate variability before and after the sessions. During the music session, subjective feelings significantly shifted toward healing and a secure/relaxed feeling and these changes were greater than those in the silent session. Heart rates (ΔHR) in the music session significantly decreased compared with those in the silent session. Other cardiac autonomic parameters such as high-frequency (HF) component and the ratio of low-frequency (LF) and HF components (LF/HF) were similar in the two sessions. In the linear regression analysis of the feelings with ΔHR and changes in LF/HF (ΔLF/HF), increases and decreases in ΔHR were correlated to the feeling axes of Fatigue-Healing and Anxiety/Tension-Security/Relaxation, whereas those in ΔLF/HF were related to the feeling axes

Technical and perceptual issues on head-related transfer functions sets for use in binaural synthesis

DEFF Research Database (Denmark)

Toledo, Daniela

of binaural synthesis in providing a realistic and/or convincing virtual sonic experience relies largely on technical and perceptual issues inherent to the HRTFs and their use, particularly on how well the spectral features of the HRTFs used match those of the listener. This PhD thesis focused on identifying...... the spectral features that cue sound localization in the mid-sagittal plane. Listening tests were conducted from which groups of individual and non-individual HRTFs that evoked the same direction were obtained. Analysis of these HRTFs suggested that the relevant spectral cues covered a broad range...

Blind estimation of the number of speech source in reverberant multisource scenarios based on binaural signals

DEFF Research Database (Denmark)

May, Tobias; van de Par, Steven

2012-01-01

In this paper we present a new approach for estimating the number of active speech sources in the presence of interfering noise sources and reverberation. First, a binaural front-end is used to detect the spatial positions of all active sound sources, resulting in a binary mask for each candidate...... on a support vector machine (SVM) classifier. A systematic analysis shows that the proposed algorithm is able to blindly determine the number and the corresponding spatial positions of speech sources in multisource scenarios and generalizes well to unknown acoustic conditions...

Analysis of the response of a photovoltaic module subjected to pulsating light of variable duty cycle

International Nuclear Information System (INIS)

Zuñiga-Reyes, Marco A.; Sevilla-Camacho, P.Y.; Robles-Ocampo, J.B.; Lopez-Villarea, S. A.

2017-01-01

The present work analyzes the time domain response of polycrystalline and amorphous silicon modules subjected to a pulsed light signal, applied under conditions of darkness and controlled temperature. The applied light has a wavelength of 625 nm, a constant power of 5 Watts, a constant frequency of 10 kHz and a variable duty cycle. The response of the modules was analyzed in both direct current (DC) and alternating current (AC). The results of the research showed differences between the waveform and the amplitude of the output voltage of each of the manufacturing technologies of the modules. To validate the obtained results, the simulation of the response of a solar cell using its equivalent circuit in CA was performed. From the experimental and simulation tests it is observed that the relation between the duty cycle and the response of the modules of different technologies can be used for the monitoring and detection of faults or for the determination of the components of the AC equivalent circuit from the solar cells. (author)

The use of listening devices to ameliorate auditory deficit in children with autism.

Science.gov (United States)

Rance, Gary; Saunders, Kerryn; Carew, Peter; Johansson, Marlin; Tan, Johanna

2014-02-01

To evaluate both monaural and binaural processing skills in a group of children with autism spectrum disorder (ASD) and to determine the degree to which personal frequency modulation (radio transmission) (FM) listening systems could ameliorate their listening difficulties. Auditory temporal processing (amplitude modulation detection), spatial listening (integration of binaural difference cues), and functional hearing (speech perception in background noise) were evaluated in 20 children with ASD. Ten of these subsequently underwent a 6-week device trial in which they wore the FM system for up to 7 hours per day. Auditory temporal processing and spatial listening ability were poorer in subjects with ASD than in matched controls (temporal: P = .014 [95% CI -6.4 to -0.8 dB], spatial: P = .003 [1.0 to 4.4 dB]), and performance on both of these basic processing measures was correlated with speech perception ability (temporal: r = -0.44, P = .022; spatial: r = -0.50, P = .015). The provision of FM listening systems resulted in improved discrimination of speech in noise (P listening devices can enhance speech perception in noise, aid social interaction, and improve educational outcomes in children with ASD. Copyright © 2014 Mosby, Inc. All rights reserved.

Visuospatial viewpoint manipulation during full-body illusion modulates subjective first-person perspective.

Science.gov (United States)

Pfeiffer, Christian; Schmutz, Valentin; Blanke, Olaf

2014-12-01

Self-consciousness is based on multisensory signals from the body. In full-body illusion (FBI) experiments, multisensory conflict was used to induce changes in three key aspects of bodily self-consciousness (BSC): self-identification (which body 'I' identify with), self-location (where 'I' am located), and first-person perspective (from where 'I' experience the world; 1PP). Here, we adapted a previous FBI protocol in which visuotactile stroking was administered by a robotic device (tactile stroking) and simultaneously rendered on the back of a virtual body (visual stroking) that participants viewed on a head-mounted display as if filmed from a posterior viewpoint of a camera. We compared the effects of two different visuospatial viewpoints on the FBI and thereby on these key aspects of BSC. During control manipulations, participants saw a no-body object instead of a virtual body (first experiment) or received asynchronous versus synchronous visuotactile stroking (second experiment). Results showed that within-subjects visuospatial viewpoint manipulations affected the subjective 1PP ratings if a virtual body was seen but had no effect for viewing a non-body object. However, visuospatial viewpoint had no effect on self-identification, but depended on the viewed object and visuotactile synchrony. Self-location depended on visuospatial viewpoint (first experiment) and visuotactile synchrony (second experiment). Our results show that the visuospatial viewpoint from which the virtual body is seen during FBIs modulates the subjective 1PP and that such viewpoint manipulations contribute to spatial aspects of BSC. We compare the present data with recent data revealing vestibular contributions to the subjective 1PP and discuss the multisensory nature of BSC and the subjective 1PP.

Improving speech-in-noise recognition for children with hearing loss: potential effects of language abilities, binaural summation, and head shadow.

Science.gov (United States)

Nittrouer, Susan; Caldwell-Tarr, Amanda; Tarr, Eric; Lowenstein, Joanna H; Rice, Caitlin; Moberly, Aaron C

2013-08-01

This study examined speech recognition in noise for children with hearing loss, compared it to recognition for children with normal hearing, and examined mechanisms that might explain variance in children's abilities to recognize speech in noise. Word recognition was measured in two levels of noise, both when the speech and noise were co-located in front and when the noise came separately from one side. Four mechanisms were examined as factors possibly explaining variance: vocabulary knowledge, sensitivity to phonological structure, binaural summation, and head shadow. Participants were 113 eight-year-old children. Forty-eight had normal hearing (NH) and 65 had hearing loss: 18 with hearing aids (HAs), 19 with one cochlear implant (CI), and 28 with two CIs. Phonological sensitivity explained a significant amount of between-groups variance in speech-in-noise recognition. Little evidence of binaural summation was found. Head shadow was similar in magnitude for children with NH and with CIs, regardless of whether they wore one or two CIs. Children with HAs showed reduced head shadow effects. These outcomes suggest that in order to improve speech-in-noise recognition for children with hearing loss, intervention needs to be comprehensive, focusing on both language abilities and auditory mechanisms.

Effects of Binaural Sensory Aids on the Development of Visual Perceptual Abilities in Visually Handicapped Infants. Final Report, April 15, 1982-November 15, 1982.

Science.gov (United States)

Hart, Verna; Ferrell, Kay

Twenty-four congenitally visually handicapped infants, aged 6-24 months, participated in a study to determine (1) those stimuli best able to elicit visual attention, (2) the stability of visual acuity over time, and (3) the effects of binaural sensory aids on both visual attention and visual acuity. Ss were dichotomized into visually handicapped…

Noise source separation of diesel engine by combining binaural sound localization method and blind source separation method

Science.gov (United States)

Yao, Jiachi; Xiang, Yang; Qian, Sichong; Li, Shengyang; Wu, Shaowei

2017-11-01

In order to separate and identify the combustion noise and the piston slap noise of a diesel engine, a noise source separation and identification method that combines a binaural sound localization method and blind source separation method is proposed. During a diesel engine noise and vibration test, because a diesel engine has many complex noise sources, a lead covering method was carried out on a diesel engine to isolate other interference noise from the No. 1-5 cylinders. Only the No. 6 cylinder parts were left bare. Two microphones that simulated the human ears were utilized to measure the radiated noise signals 1 m away from the diesel engine. First, a binaural sound localization method was adopted to separate the noise sources that are in different places. Then, for noise sources that are in the same place, a blind source separation method is utilized to further separate and identify the noise sources. Finally, a coherence function method, continuous wavelet time-frequency analysis method, and prior knowledge of the diesel engine are combined to further identify the separation results. The results show that the proposed method can effectively separate and identify the combustion noise and the piston slap noise of a diesel engine. The frequency of the combustion noise and the piston slap noise are respectively concentrated at 4350 Hz and 1988 Hz. Compared with the blind source separation method, the proposed method has superior separation and identification effects, and the separation results have fewer interference components from other noise.

A variant in ANKK1 modulates acute subjective effects of cocaine: a preliminary study

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Spellicy, Catherine J.; Harding, Mark J.; Hamon, Sara C.; Mahoney, James J.; Reyes, Jennifer A.; Kosten, Thomas R.; Newton, Thomas F.; De La Garza, Richard; Nielsen, David A.

2014-01-01

This study aimed to evaluate whether functional variants in the ankyrin repeat and kinase domain-containing 1 gene (ANKK1) and/or the dopamine receptor D2 gene (DRD2) modulate the subjective effects (reward or non-reward response to a stimulus) produced by cocaine administration. Cocaine-dependent participants (N = 47) were administered 40 mg of cocaine or placebo at time 0, and a subjective effects questionnaire (visual analog scale) was administered 15 minutes prior to cocaine administration, and at 5, 10,15, and 20 minutes following administration. The influence of polymorphisms in the ANKK1 and DRD2 genes on subjective experience of cocaine in the laboratory was tested. Participants with a T allele of ANKK1 rs1800497 experienced greater subjective ‘high’ (p = 0.00006), ‘any drug effect’ (p = 0.0003), and ‘like’ (p = 0.0004) relative to the CC genotype group. Although the variant in the DRD2 gene was shown to be associated with subjective effects, LD analysis revealed this association was driven by the ANKK1 rs1800497 variant. A participant’s ANKK1 genotype may identify individuals who are likely to experience greater positive subjective effects following cocaine exposure, including greater ‘high’ and ‘like’, and these individuals may have increased vulnerability to continue using cocaine or they may be at greater risk to relapse during periods of abstinence. However, these results are preliminary and replication is necessary to confirm these findings. PMID:24528631

Evidence of Rapid Modulation by Social Information of Subjective, Physiological, and Neural Responses to Emotional Expressions.

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Mermillod, Martial; Grynberg, Delphine; Pio-Lopez, Léo; Rychlowska, Magdalena; Beffara, Brice; Harquel, Sylvain; Vermeulen, Nicolas; Niedenthal, Paula M; Dutheil, Frédéric; Droit-Volet, Sylvie

2017-01-01

Recent research suggests that conceptual or emotional factors could influence the perceptual processing of stimuli. In this article, we aimed to evaluate the effect of social information (positive, negative, or no information related to the character of the target) on subjective (perceived and felt valence and arousal), physiological (facial mimicry) as well as on neural (P100 and N170) responses to dynamic emotional facial expressions (EFE) that varied from neutral to one of the six basic emotions. Across three studies, the results showed reduced ratings of valence and arousal of EFE associated with incongruent social information (Study 1), increased electromyographical responses (Study 2), and significant modulation of P100 and N170 components (Study 3) when EFE were associated with social (positive and negative) information (vs. no information). These studies revealed that positive or negative social information reduces subjective responses to incongruent EFE and produces a similar neural and physiological boost of the early perceptual processing of EFE irrespective of their congruency. In conclusion, the article suggests that the presence of positive or negative social context modulates early physiological and neural activity preceding subsequent behavior.

Evidence of Rapid Modulation by Social Information of Subjective, Physiological, and Neural Responses to Emotional Expressions

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Martial Mermillod

2018-01-01

Full Text Available Recent research suggests that conceptual or emotional factors could influence the perceptual processing of stimuli. In this article, we aimed to evaluate the effect of social information (positive, negative, or no information related to the character of the target on subjective (perceived and felt valence and arousal, physiological (facial mimicry as well as on neural (P100 and N170 responses to dynamic emotional facial expressions (EFE that varied from neutral to one of the six basic emotions. Across three studies, the results showed reduced ratings of valence and arousal of EFE associated with incongruent social information (Study 1, increased electromyographical responses (Study 2, and significant modulation of P100 and N170 components (Study 3 when EFE were associated with social (positive and negative information (vs. no information. These studies revealed that positive or negative social information reduces subjective responses to incongruent EFE and produces a similar neural and physiological boost of the early perceptual processing of EFE irrespective of their congruency. In conclusion, the article suggests that the presence of positive or negative social context modulates early physiological and neural activity preceding subsequent behavior.

The Opponent Channel Population Code of Sound Location Is an Efficient Representation of Natural Binaural Sounds

Science.gov (United States)

Młynarski, Wiktor

2015-01-01

In mammalian auditory cortex, sound source position is represented by a population of broadly tuned neurons whose firing is modulated by sounds located at all positions surrounding the animal. Peaks of their tuning curves are concentrated at lateral position, while their slopes are steepest at the interaural midline, allowing for the maximum localization accuracy in that area. These experimental observations contradict initial assumptions that the auditory space is represented as a topographic cortical map. It has been suggested that a “panoramic” code has evolved to match specific demands of the sound localization task. This work provides evidence suggesting that properties of spatial auditory neurons identified experimentally follow from a general design principle- learning a sparse, efficient representation of natural stimuli. Natural binaural sounds were recorded and served as input to a hierarchical sparse-coding model. In the first layer, left and right ear sounds were separately encoded by a population of complex-valued basis functions which separated phase and amplitude. Both parameters are known to carry information relevant for spatial hearing. Monaural input converged in the second layer, which learned a joint representation of amplitude and interaural phase difference. Spatial selectivity of each second-layer unit was measured by exposing the model to natural sound sources recorded at different positions. Obtained tuning curves match well tuning characteristics of neurons in the mammalian auditory cortex. This study connects neuronal coding of the auditory space with natural stimulus statistics and generates new experimental predictions. Moreover, results presented here suggest that cortical regions with seemingly different functions may implement the same computational strategy-efficient coding. PMID:25996373

A Subjective Evaluation of the Minimum Audible Channel Separation in Binaural Reproduction Systems Through Loudspeakers

DEFF Research Database (Denmark)

Lacouture Parodi, Yesenia; Rubak, Per

2010-01-01

To evaluate the performance of crosstalk cancellation systems the channel separation is usually used as parameter.  However, no systematic evaluation of the minimum audible channel separation has been found in the literature known by the authors.  This paper describes a set of subjective experime......To evaluate the performance of crosstalk cancellation systems the channel separation is usually used as parameter.  However, no systematic evaluation of the minimum audible channel separation has been found in the literature known by the authors.  This paper describes a set of subjective...... simulated.  Results indicate that  in order to avoid lateralization the  channel separation should be below -15dB for most of the stimuli and around -20dB for broad-band noise....

Relating hearing loss and executive functions to hearing aid users’ preference for, and speech recognition with, different combinations of binaural noise reduction and microphone directionality

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Tobias eNeher

2014-12-01

Full Text Available Knowledge of how executive functions relate to preferred hearing aid (HA processing is sparse and seemingly inconsistent with related knowledge for speech recognition outcomes. This study thus aimed to find out if (1 performance on a measure of reading span (RS is related to preferred binaural noise reduction (NR strength, (2 similar relations exist for two different, nonverbal measures of executive function, (3 pure-tone average hearing loss (PTA, signal-to-noise ratio (SNR, and microphone directionality (DIR also influence preferred NR strength, and (4 preference and speech recognition outcomes are similar. Sixty elderly HA users took part. Six HA conditions consisting of omnidirectional or cardioid microphones followed by inactive, moderate, or strong binaural NR as well as linear amplification were tested. Outcome was assessed at fixed SNRs using headphone simulations of a frontal target talker in a busy cafeteria. Analyses showed positive effects of active NR and DIR on preference, and negative and positive effects of, respectively, strong NR and DIR on speech recognition. Also, while moderate NR was the most preferred NR setting overall, preference for strong NR increased with SNR. No relation between RS and preference was found. However, larger PTA was related to weaker preference for inactive NR and stronger preference for strong NR for both microphone modes. Equivalent (but weaker relations between worse performance on one nonverbal measure of executive function and the HA conditions without DIR were found. For speech recognition, there were relations between HA condition, PTA, and RS, but their pattern differed from that for preference. Altogether, these results indicate that, while moderate NR works well in general, a notable proportion of HA users prefer stronger NR. Furthermore, PTA and executive functions can account for some of the variability in preference for, and speech recognition with, different binaural NR and DIR settings.

Development and evaluation of the LiSN & learn auditory training software for deficit-specific remediation of binaural processing deficits in children: preliminary findings.

Science.gov (United States)

Cameron, Sharon; Dillon, Harvey

2011-01-01

The LiSN & Learn auditory training software was developed specifically to improve binaural processing skills in children with suspected central auditory processing disorder who were diagnosed as having a spatial processing disorder (SPD). SPD is defined here as a condition whereby individuals are deficient in their ability to use binaural cues to selectively attend to sounds arriving from one direction while simultaneously suppressing sounds arriving from another. As a result, children with SPD have difficulty understanding speech in noisy environments, such as in the classroom. To develop and evaluate the LiSN & Learn auditory training software for children diagnosed with the Listening in Spatialized Noise-Sentences Test (LiSN-S) as having an SPD. The LiSN-S is an adaptive speech-in-noise test designed to differentially diagnose spatial and pitch-processing deficits in children with suspected central auditory processing disorder. Participants were nine children (aged between 6 yr, 9 mo, and 11 yr, 4 mo) who performed outside normal limits on the LiSN-S. In a pre-post study of treatment outcomes, participants trained on the LiSN & Learn for 15 min per day for 12 weeks. Participants acted as their own control. Participants were assessed on the LiSN-S, as well as tests of attention and memory and a self-report questionnaire of listening ability. Performance on all tasks was reassessed after 3 mo where no further training occurred. The LiSN & Learn produces a three-dimensional auditory environment under headphones on the user's home computer. The child's task was to identify a word from a target sentence presented in background noise. A weighted up-down adaptive procedure was used to adjust the signal level of the target based on the participant's response. On average, speech reception thresholds on the LiSN & Learn improved by 10 dB over the course of training. As hypothesized, there were significant improvements in posttraining performance on the LiSN-S conditions

Silicon Carbide (SiC) Device and Module Reliability, Performance of a Loop Heat Pipe Subjected to a Phase-Coupled Heat Input to an Acceleration Field

Science.gov (United States)

2016-05-01

AFRL-RQ-WP-TR-2016-0108 SILICON CARBIDE (SiC) DEVICE AND MODULE RELIABILITY Performance of a Loop Heat Pipe Subjected to a Phase-Coupled...CARBIDE (SiC) DEVICE AND MODULE RELIABILITY Performance of a Loop Heat Pipe Subjected to a Phase-Coupled Heat Input to an Acceleration Field 5a...Shukla, K., “Thermo-fluid dynamics of Loop Heat Pipe Operation,” International Communications in Heat and Mass Transfer , Vol. 35, No. 8, 2008, pp

Monaural and binaural response properties of neurons in the inferior colliculus of the rabbit: effects of sodium pentobarbital.

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Kuwada, S; Batra, R; Stanford, T R

1989-02-01

1. We studied the effects of sodium pentobarbital on 22 neurons in the inferior colliculus (IC) of the rabbit. We recorded changes in the sensitivity of these neurons to monaural stimulation and to ongoing interaural time differences (ITDs). Monaural stimuli were tone bursts at or near the neuron's best frequency. The ITD was varied by delivering tones that differed by 1 Hz to the two ears, resulting in a 1-Hz binaural beat. 2. We assessed a neuron's ITD sensitivity by calculating three measures from the responses to binaural beats: composite delay, characteristic delay (CD), and characteristic phase (CP). To obtain the composite delay, we first derived period histograms by averaging, showing the response at each stimulating frequency over one period of the beat frequency. Second, the period histograms were replotted as a function of their equivalent interaural delay and then averaged together to yield the composite delay curve. Last, we calculated the composite peak or trough delay by fitting a parabola to the peak or trough of this composite curve. The composite delay curve represents the average response to all frequencies within the neuron's responsive range, and the peak reflects the interaural delay that produces the maximum response. The CD and CP were estimated from a weighted fit of a regression line to the plot of the mean interaural phase of the response versus the stimulating frequency. The slope and phase intercept of this regression line yielded estimates of CD and CP, respectively. These two quantities are thought to reflect the mechanism of ITD sensitivity, which involves the convergence of phase-locked inputs on a binaural cell. The CD estimates the difference in the time required for the two inputs to travel from either ear to this cell, whereas the CP reflects the interaural phase difference of the inputs at this cell. 3. Injections of sodium pentobarbital at subsurgical dosages (less than 25 mg/kg) almost invariably altered the neuron's response

Objective measures of binaural masking level differences and comodulation masking release based on late auditory evoked potentials.

Science.gov (United States)

Epp, Bastian; Yasin, Ifat; Verhey, Jesko L

2013-12-01

The audibility of important sounds is often hampered due to the presence of other masking sounds. The present study investigates if a correlate of the audibility of a tone masked by noise is found in late auditory evoked potentials measured from human listeners. The audibility of the target sound at a fixed physical intensity is varied by introducing auditory cues of (i) interaural target signal phase disparity and (ii) coherent masker level fluctuations in different frequency regions. In agreement with previous studies, psychoacoustical experiments showed that both stimulus manipulations result in a masking release (i: binaural masking level difference; ii: comodulation masking release) compared to a condition where those cues are not present. Late auditory evoked potentials (N1, P2) were recorded for the stimuli at a constant masker level, but different signal levels within the same set of listeners who participated in the psychoacoustical experiment. The data indicate differences in N1 and P2 between stimuli with and without interaural phase disparities. However, differences for stimuli with and without coherent masker modulation were only found for P2, i.e., only P2 is sensitive to the increase in audibility, irrespective of the cue that caused the masking release. The amplitude of P2 is consistent with the psychoacoustical finding of an addition of the masking releases when both cues are present. Even though it cannot be concluded where along the auditory pathway the audibility is represented, the P2 component of auditory evoked potentials is a candidate for an objective measure of audibility in the human auditory system. Copyright © 2013 Elsevier B.V. All rights reserved.

Tinnitus: distinguishing between subjectively perceived loudness and tinnitus-related distress.

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Elisabeth Wallhäusser-Franke

Full Text Available OBJECTIVES: Overall success of current tinnitus therapies is low, which may be due to the heterogeneity of tinnitus patients. Therefore, subclassification of tinnitus patients is expected to improve therapeutic allocation, which, in turn, is hoped to improve therapeutic success for the individual patient. The present study aims to define factors that differentially influence subjectively perceived tinnitus loudness and tinnitus-related distress. METHODS: In a questionnaire-based cross-sectional survey, the data of 4705 individuals with tinnitus were analyzed. The self-report questionnaire contained items about subjective tinnitus loudness, type of onset, awareness and localization of the tinnitus, hearing impairment, chronic comorbidities, sleep quality, and psychometrically validated questionnaires addressing tinnitus-related distress, depressivity, anxiety, and somatic symptom severity. In a binary step-wise logistic regression model, we tested the predictive power of these variables on subjective tinnitus loudness and tinnitus-related distress. RESULTS: The present data contribute to the distinction between subjective tinnitus loudness and tinnitus-related distress. Whereas subjective loudness was associated with permanent awareness and binaural localization of the tinnitus, tinnitus-related distress was associated with depressivity, anxiety, and somatic symptom severity. CONCLUSIONS: Subjective tinnitus loudness and the potential presence of severe depressivity, anxiety, and somatic symptom severity should be assessed separately from tinnitus-related distress. If loud tinnitus is the major complaint together with mild or moderate tinnitus-related distress, therapies should focus on auditory perception. If levels of depressivity, anxiety or somatic symptom severity are severe, therapies and further diagnosis should focus on these symptoms at first.

Tinnitus: Distinguishing between Subjectively Perceived Loudness and Tinnitus-Related Distress

Science.gov (United States)

Wallhäusser-Franke, Elisabeth; Brade, Joachim; Balkenhol, Tobias; D'Amelio, Roberto; Seegmüller, Andrea; Delb, Wolfgang

2012-01-01

Objectives Overall success of current tinnitus therapies is low, which may be due to the heterogeneity of tinnitus patients. Therefore, subclassification of tinnitus patients is expected to improve therapeutic allocation, which, in turn, is hoped to improve therapeutic success for the individual patient. The present study aims to define factors that differentially influence subjectively perceived tinnitus loudness and tinnitus-related distress. Methods In a questionnaire-based cross-sectional survey, the data of 4705 individuals with tinnitus were analyzed. The self-report questionnaire contained items about subjective tinnitus loudness, type of onset, awareness and localization of the tinnitus, hearing impairment, chronic comorbidities, sleep quality, and psychometrically validated questionnaires addressing tinnitus-related distress, depressivity, anxiety, and somatic symptom severity. In a binary step-wise logistic regression model, we tested the predictive power of these variables on subjective tinnitus loudness and tinnitus-related distress. Results The present data contribute to the distinction between subjective tinnitus loudness and tinnitus-related distress. Whereas subjective loudness was associated with permanent awareness and binaural localization of the tinnitus, tinnitus-related distress was associated with depressivity, anxiety, and somatic symptom severity. Conclusions Subjective tinnitus loudness and the potential presence of severe depressivity, anxiety, and somatic symptom severity should be assessed separately from tinnitus-related distress. If loud tinnitus is the major complaint together with mild or moderate tinnitus-related distress, therapies should focus on auditory perception. If levels of depressivity, anxiety or somatic symptom severity are severe, therapies and further diagnosis should focus on these symptoms at first. PMID:22529921

Bioeffects of Radiofrequency Radiation: A Review Pertinent to Air Force Operations.

Science.gov (United States)

1983-03-01

standard audiograms. Because such audiograms do not test hearing above 8 kHz, binaural hearing thresholds were also determined for seven of the subjects for...between RFR perception and hearing ability above 8 kHz as determined from the binaural thresholds. The average threshold energy density for the humans...perception thresholds on pulse width. They also reported that subjects could detect beat fre- quencies when concurrently presented with 8-kHz AF sound

A single dose of dark chocolate increases parasympathetic modulation and heart rate variability in healthy subjects

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Ana Amélia Machado DUARTE

Full Text Available ABSTRACT Objective: The aim of this study was to investigate the acute effect of a single dose of dark chocolate (70% cocoa on blood pressure and heart rate variability. Methods: Thirty-one healthy subjects (aged 18-25 years; both sexes were divided into two groups: 10 subjects in the white chocolate (7.4 g group and 21 in the dark chocolate (10 g group; measurements were performed at the university's physiology lab. An electrocardiogram measured the sympathovagal balance by spectral and symbolic analysis. Results: A single dose of dark chocolate significantly reduced systolic blood pressure and heart rate. After consuming 10 g of dark chocolate, significant increases were observed for heart rate variability, standard deviation of RR intervals standard deviation of all NN intervals, square root of the mean squared differences between adjacent normal RR intervals root mean square of successive differences, and an increase in the high frequency component in absolute values, representing the parasympathetic modulation. Conclusion: In conclusion the importance of our results lies in the magnitude of the response provoked by a single dose of cocoa. Just 10 g of cocoa triggered a significant increase in parasympathetic modulation and heart rate variability. These combined effects can potentially increase life expectancy because a reduction in heart rate variability is associated with several cardiovascular diseases and higher mortality.

The effects of asymmetric directional microphone fittings on acceptance of background noise.

Science.gov (United States)

Kim, Jong S; Bryan, Melinda Freyaldenhoven

2011-05-01

The effects of asymmetric directional microphone fittings (i.e., an omnidirectional microphone on one ear and a directional microphone on the other) on speech understanding in noise and acceptance of background noise were investigated in 15 full-time hearing aid users. Subjects were fitted binaurally with four directional microphone conditions (i.e., binaural omnidirectional, right asymmetric directional, left asymmetric directional and binaural directional microphones) using Siemens Intuis Directional behind-the-ear hearing aids. Speech understanding in noise was assessed using the Hearing in Noise Test, and acceptance of background noise was assessed using the Acceptable Noise Level procedure. Speech was presented from 0° while noise was presented from 180° azimuth. The results revealed that speech understanding in noise improved when using asymmetric directional microphones compared to binaural omnidirectional microphone fittings and was not significantly hindered compared to binaural directional microphone fittings. The results also revealed that listeners accepted more background noise when fitted with asymmetric directional microphones as compared to binaural omnidirectional microphones. Lastly, the results revealed that the acceptance of noise was further increased for the binaural directional microphones when compared to the asymmetric directional microphones, maximizing listeners' willingness to accept background noise in the presence of noise. Clinical implications will be discussed.

Regional cerebral blood flow during comprehension and speech (in cerebrally healthy subjects)

International Nuclear Information System (INIS)

Lechevalier, B.; Petit, M.C.; Eustache, F.; Lambert, J.; Chapon, F.; Viader, F.

1989-01-01

Regional cerebral blood flow (rCBF) was measured by the xenon-133 inhalation method in 10 cerebrally healthy subjects at rest and during linguistic activation tests. These consisted of a comprehension test (binaural listening to a narrative text) and a speech test (making sentences from a list of words presented orally at 30-s intervals). The comprehension task induced a moderate increase in the mean right CBF and in both inferior parietal areas, whereas the speech test resulted in a diffuse increase in the mean CBF of both hemispheres, predominating regionally in both inferior parietal, left operculary, and right upper motor and premotor areas. It is proposed that the activation pattern induced by linguistic stimulation depends on not only specific factors, such as syntactic and semantic aspects of language, but also the contents of the material proposed and the attention required by the test situation

Emotion modulation of the startle reflex in essential tremor: Blunted reactivity to unpleasant and pleasant pictures.

Science.gov (United States)

Lafo, Jacob A; Mikos, Ania; Mangal, Paul C; Scott, Bonnie M; Trifilio, Erin; Okun, Michael S; Bowers, Dawn

2017-01-01

Essential tremor is a highly prevalent movement disorder characterized by kinetic tremor and mild cognitive-executive changes. These features are commonly attributed to abnormal cerebellar changes, resulting in disruption of cerebellar-thalamo-cortical networks. Less attention has been paid to alterations in basic emotion processing in essential tremor, despite known cerebellar-limbic interconnectivity. In the current study, we tested the hypothesis that a psychophysiologic index of emotional reactivity, the emotion modulated startle reflex, would be muted in individuals with essential tremor relative to controls. Participants included 19 essential tremor patients and 18 controls, who viewed standard sets of unpleasant, pleasant, and neutral pictures for six seconds each. During picture viewing, white noise bursts were binaurally presented to elicit startle eyeblinks measured over the orbicularis oculi. Consistent with past literature, controls' startle eyeblink responses were modulated according to picture valence (unpleasant > neutral > pleasant). In essential tremor participants, startle eyeblinks were not modulated by emotion. This modulation failure was not due to medication effects, nor was it due to abnormal appraisal of emotional picture content. Neuroanatomically, it remains unclear whether diminished startle modulation in essential tremor is secondary to aberrant cerebellar input to the amygdala, which is involved in priming the startle response in emotional contexts, or due to more direct disruption between the cerebellum and brainstem startle circuitry. If the former is correct, these findings may be the first to reveal dysregulation of emotional networks in essential tremor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Corticofugal modulation of initial neural processing of sound information from the ipsilateral ear in the mouse.

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Xiuping Liu

2010-11-01

Full Text Available Cortical neurons implement a high frequency-specific modulation of subcortical nuclei that includes the cochlear nucleus. Anatomical studies show that corticofugal fibers terminating in the auditory thalamus and midbrain are mostly ipsilateral. Differently, corticofugal fibers terminating in the cochlear nucleus are bilateral, which fits to the needs of binaural hearing that improves hearing quality. This leads to our hypothesis that corticofugal modulation of initial neural processing of sound information from the contralateral and ipsilateral ears could be equivalent or coordinated at the first sound processing level.With the focal electrical stimulation of the auditory cortex and single unit recording, this study examined corticofugal modulation of the ipsilateral cochlear nucleus. The same methods and procedures as described in our previous study of corticofugal modulation of contralateral cochlear nucleus were employed simply for comparison. We found that focal electrical stimulation of cortical neurons induced substantial changes in the response magnitude, response latency and receptive field of ipsilateral cochlear nucleus neurons. Cortical stimulation facilitated auditory response and shortened the response latency of physiologically matched neurons whereas it inhibited auditory response and lengthened the response latency of unmatched neurons. Finally, cortical stimulation shifted the best frequencies of cochlear neurons towards those of stimulated cortical neurons.Our data suggest that cortical neurons enable a high frequency-specific remodelling of sound information processing in the ipsilateral cochlear nucleus in the same manner as that in the contralateral cochlear nucleus.

Are two ears not better than one?

Science.gov (United States)

McArdle, Rachel A; Killion, Mead; Mennite, Monica A; Chisolm, Theresa H

2012-03-01

The decision to fit one or two hearing aids in individuals with binaural hearing loss has been debated for years. Although some 78% of U.S. hearing aid fittings are binaural (Kochkin , 2010), Walden and Walden (2005) presented data showing that 82% (23 of 28 patients) of their sample obtained significantly better speech recognition in noise scores when wearing one hearing aid as opposed to two. To conduct two new experiments to fuel the monaural/binaural debate. The first experiment was a replication of Walden and Walden (2005), whereas the second experiment examined the use of binaural cues to improve speech recognition in noise. A repeated measures experimental design. Twenty veterans (aged 59-85 yr), with mild to moderately severe binaurally symmetrical hearing loss who wore binaural hearing aids were recruited from the Audiology Department at the Bay Pines VA Healthcare System. Experiment 1 followed the procedures of the Walden and Walden study, where signal-to-noise ratio (SNR) loss was measured using the Quick Speech-in-Noise (QuickSIN) test on participants who were aided with their current hearing aids. Signal and noise were presented in the sound booth at 0° azimuth under five test conditions: (1) right ear aided, (2) left ear aided, (3) both ears aided, (4) right ear aided, left ear plugged, and (5) unaided. The opposite ear in (1) and (2) was left open. In Experiment 2, binaural Knowles Electronics Manikin for Acoustic Research (KEMAR) manikin recordings made in Lou Malnati's pizza restaurant during a busy period provided a typical real-world noise, while prerecorded target sentences were presented through a small loudspeaker located in front of the KEMAR manikin. Subjects listened to the resulting binaural recordings through insert earphones under the following four conditions: (1) binaural, (2) diotic, (3) monaural left, and (4) monaural right. Results of repeated measures ANOVAs demonstrated that the best speech recognition in noise performance was

Influencia de la estimulación sonora binaural en la generación de ondas cerebrales. Estudio electroencefalográfico

OpenAIRE

González Velasco, Pedro Miguel

2013-01-01

Introducción y objetivos. La audición binaural permite al sistema auditivo realizar un correcto análisis de la información que portan las ondas sonoras al posibilitar la comparación de la señal que llega a cada oído. La relación de ambos lados de la vía auditiva sucede casi desde el inicio de la misma, ya en el tronco cerebral, mediante decusaciones de fibras al lado contralateral de la vía auditiva. De esta manera, la estimulación sonora influye en la actividad del sistema nervioso y, pos...

Merging physical parameters and laboratory subjective ratings for the soundscape assessment of urban squares.

Science.gov (United States)

Brambilla, Giovanni; Maffei, Luigi; Di Gabriele, Maria; Gallo, Veronica

2013-07-01

An experimental study was carried out in 20 squares in the center of Rome, covering a wide range of different uses, sonic environments, geometry, and architectural styles. Soundwalks along the perimeter of each square were performed during daylight and weekdays taking binaural and video recordings, as well as spot measurements of illuminance. The cluster analysis performed on the physical parameters, not only acoustic, provided two clusters that are in satisfactory agreement with the "a priori" classification. Applying the principal component analysis (PCA) to five physical parameters, two main components were obtained which might be associated to two environmental features, namely, "chaotic/calm" and "open/enclosed." On the basis of these two features, six squares were selected for the laboratory audio-video tests where 32 subjects took part filling in a questionnaire. The PCA performed on the subjective ratings on the sonic environment showed two main components which might be associated to two emotional meanings, namely, "calmness" and "vibrancy." The linear regression modeling between five objective parameters and the mean value of subjective ratings on chaotic/calm and enclosed/open attributes showed a good correlation. Notwithstanding these interesting results being limited to the specific data set, it is worth pointing out that the complexity of the soundscape quality assessment can be more comprehensively examined merging the field measurements of physical parameters with the subjective ratings provided by field and/or laboratory tests.

Hibiscus and lemon verbena polyphenols modulate appetite-related biomarkers in overweight subjects: a randomized controlled trial.

Science.gov (United States)

Boix-Castejón, Marina; Herranz-López, María; Pérez Gago, Alberto; Olivares-Vicente, Mariló; Caturla, Nuria; Roche, Enrique; Micol, Vicente

2018-06-04

Plant-derived polyphenols have shown potential to alleviate obesity-related pathologies by a multi-targeted mechanism in animal models and human intervention studies. A dietary supplement based on a combination of Lippia citriodora (LC) and Hibiscus sabdariffa (HS) polyphenolic extracts was assayed in a double blind and placebo-controlled intervention study with 54 overweight subjects. Blood pressure, body weight, height, triceps, biceps and abdominal skinfold thickness, and arm and abdominal circumferences were taken at the baseline, 30 and 60 days of the intervention period. The validated Visual Analogue Scale used to record hunger and satiety-related sensations was passed at the beginning and at 15, 30, 45 and 60 days of the intervention. Subjective health status was assessed through the validated SF-36 questionnaire at the beginning and end of the study. Finally, plasma from fasting blood samples was obtained at the beginning, 30 and 60 days of the study. The results showed an improvement of anthropometric measurements, decreased blood pressure and heart rate and a more positive perception in the overall health status. We also observed that plant polyphenols increased anorexigenic hormones (glucagon-like peptide-1) and decreased orexigenic hormones (ghrelin). Based on previous evidence we postulate that AMP-activated protein kinase may have a role in such effects through its capability to modulate energy homeostasis, total daily energy expenditure and lipid management. Although further research may be required, we propose that this polyphenolic combination may be used for weight management by increasing long-term weight loss maintenance through the modulation of appetite biomarkers. This may help to avoid the undesired weight regain typical of calorie restriction diets.

Modulation of electroencephalograph activity by manual acupuncture stimulation in healthy subjects: An autoregressive spectral analysis

International Nuclear Information System (INIS)

Yi Guo-Sheng; Wang Jiang; Deng Bin; Wei Xi-Le; Han Chun-Xiao

2013-01-01

To investigate whether and how manual acupuncture (MA) modulates brain activities, we design an experiment where acupuncture at acupoint ST36 of the right leg is used to obtain electroencephalograph (EEG) signals in healthy subjects. We adopt the autoregressive (AR) Burg method to estimate the power spectrum of EEG signals and analyze the relative powers in delta (0 Hz–4 Hz), theta (4 Hz–8 Hz), alpha (8 Hz–13 Hz), and beta (13 Hz–30 Hz) bands. Our results show that MA at ST36 can significantly increase the EEG slow wave relative power (delta band) and reduce the fast wave relative powers (alpha and beta bands), while there are no statistical differences in theta band relative power between different acupuncture states. In order to quantify the ratio of slow to fast wave EEG activity, we compute the power ratio index. It is found that the MA can significantly increase the power ratio index, especially in frontal and central lobes. All the results highlight the modulation of brain activities with MA and may provide potential help for the clinical use of acupuncture. The proposed quantitative method of acupuncture signals may be further used to make MA more standardized. (interdisciplinary physics and related areas of science and technology)

Subjective Response to Foot-Fall Noise, Including Localization of the Source Position

DEFF Research Database (Denmark)

Brunskog, Jonas; Hwang, Ha Dong; Jeong, Cheol-Ho

2011-01-01

annoyance, using simulated binaural room impulse responses, with sources being a moving point source or a nonmoving surface source, and rooms being a room with a reverberation time of 0.5 s or an anechoic room. The paper concludes that no strong effect of the source localization on the annoyance can...

Southeast PAVE PAWS Radar System. Environmental Assessment.

Science.gov (United States)

1983-03-01

reported, including fatigue, irritability, sleepiness, partial loss of memory, lower heart- beat rates, hypertension, hypotension, cardiac pain, and...Because such audiograms do not test hearing above 8 klz, binaural hearing thresholds were also determined for seven of the subjects for frequencies...perception and hearing ability above 8 kl:z as determined from the binaural thresholds. The average threshold pulse power density for 15-microsecond

Synthetic Aperture Computation as the Head is Turned in Binaural Direction Finding

Directory of Open Access Journals (Sweden)

Duncan Tamsett

2017-03-01

Full Text Available Binaural systems measure instantaneous time/level differences between acoustic signals received at the ears to determine angles λ between the auditory axis and directions to acoustic sources. An angle λ locates a source on a small circle of colatitude (a lamda circle on a sphere symmetric about the auditory axis. As the head is turned while listening to a sound, acoustic energy over successive instantaneous lamda circles is integrated in a virtual/subconscious field of audition. The directions in azimuth and elevation to maxima in integrated acoustic energy, or to points of intersection of lamda circles, are the directions to acoustic sources. This process in a robotic system, or in nature in a neural implementation equivalent to it, delivers its solutions to the aurally informed worldview. The process is analogous to migration applied to seismic profiler data, and to that in synthetic aperture radar/sonar systems. A slanting auditory axis, e.g., possessed by species of owl, leads to the auditory axis sweeping the surface of a cone as the head is turned about a single axis. Thus, the plane in which the auditory axis turns continuously changes, enabling robustly unambiguous directions to acoustic sources to be determined.

Objective measures of binaural masking level differences and comodulation masking release based on late auditory evoked potentials

DEFF Research Database (Denmark)

Epp, Bastian; Yasin, Ifat; Verhey, Jesko L.

2013-01-01

at a fixed physical intensity is varied by introducing auditory cues of (i) interaural target signal phase disparity and (ii) coherent masker level fluctuations in different frequency regions. In agreement with previous studies, psychoacoustical experiments showed that both stimulus manipulations result......The audibility of important sounds is often hampered due to the presence of other masking sounds. The present study investigates if a correlate of the audibility of a tone masked by noise is found in late auditory evoked potentials measured from human listeners. The audibility of the target sound...... in a masking release (i: binaural masking level difference; ii: comodulation masking release) compared to a condition where those cues are not present. Late auditory evoked potentials (N1, P2) were recorded for the stimuli at a constant masker level, but different signal levels within the same set of listeners...

Neural interface methods and apparatus to provide artificial sensory capabilities to a subject

Energy Technology Data Exchange (ETDEWEB)

Buerger, Stephen P.; Olsson, III, Roy H.; Wojciechowski, Kenneth E.; Novick, David K.; Kholwadwala, Deepesh K.

2017-01-24

Embodiments of neural interfaces according to the present invention comprise sensor modules for sensing environmental attributes beyond the natural sensory capability of a subject, and communicating the attributes wirelessly to an external (ex-vivo) portable module attached to the subject. The ex-vivo module encodes and communicates the attributes via a transcutaneous inductively coupled link to an internal (in-vivo) module implanted within the subject. The in-vivo module converts the attribute information into electrical neural stimuli that are delivered to a peripheral nerve bundle within the subject, via an implanted electrode. Methods and apparatus according to the invention incorporate implantable batteries to power the in-vivo module allowing for transcutaneous bidirectional communication of low voltage (e.g. on the order of 5 volts) encoded signals as stimuli commands and neural responses, in a robust, low-error rate, communication channel with minimal effects to the subjects' skin.

Predicting masking release of lateralized speech

DEFF Research Database (Denmark)

Chabot-Leclerc, Alexandre; MacDonald, Ewen; Dau, Torsten

2016-01-01

. The largest masking release (MR) was observed when all maskers were on the opposite side of the target. The data in the conditions containing only energetic masking and modulation masking could be accounted for using a binaural extension of the speech-based envelope power spectrum model [sEPSM; Jørgensen et...... al., 2013, J. Acoust. Soc. Am. 130], which uses a short-term equalization-cancellation process to model binaural unmasking. In the conditions where informational masking (IM) was involved, the predicted SRTs were lower than the measured values because the model is blind to confusions experienced...

Cerebral responses and role of the prefrontal cortex in conditioned pain modulation: an fMRI study in healthy subjects

Science.gov (United States)

Bogdanov, Volodymyr B.; Viganò, Alessandro; Noirhomme, Quentin; Bogdanova, Olena V.; Guy, Nathalie; Laureys, Steven; Renshaw, Perry F.; Dallel, Radhouane; Phillips, Christophe; Schoenen, Jean

2017-01-01

The mechanisms underlying conditioned pain modulation (CPM) are multifaceted. We searched for a link between individual differences in prefrontal cortex activity during multi-trial heterotopic noxious cold conditioning and modulation of the cerebral response to phasic heat pain. In 24 healthy female subjects, we conditioned laser heat stimuli to the left hand by applying alternatively ice-cold or lukewarm compresses to the right foot. We compared pain ratings with cerebral fMRI BOLD responses. We also analyzed the relation between CPM and BOLD changes produced by the heterotopic cold conditioning itself, as well as the impact of anxiety and habituation of cold-pain ratings. Specific cerebral activation was identified in precuneus and left posterior insula/SII, respectively, during early and sustained phases of cold application. During cold conditioning, laser pain decreased (n = 7), increased (n = 10) or stayed unchanged (n = 7). At the individual level, the psychophysical effect was directly proportional to the cold-induced modulation of the laser-induced BOLD response in left posterior insula/SII. The latter correlated with the BOLD response recorded 80 s earlier during the initial 10-s phase of cold application in anterior cingulate, orbitofrontal and lateral prefrontal cortices. High anxiety and habituation of cold pain were associated with greater laser heat-induced pain during heterotopic cold stimulation. The habituation was also linked to the early cold-induced orbitofrontal responses. We conclude that individual differences in conditioned pain modulation are related to different levels of prefrontal cortical activation by the early part of the conditioning stimulus, possibly due to different levels in trait anxiety. PMID:25461267

Different event-related patterns of gamma-band power in brain waves of fast- and slow-reacting subjects.

Science.gov (United States)

Jokeit, H; Makeig, S

1994-01-01

Fast- and slow-reacting subjects exhibit different patterns of gamma-band electroencephalogram (EEG) activity when responding as quickly as possible to auditory stimuli. This result appears to confirm long-standing speculations of Wundt that fast- and slow-reacting subjects produce speeded reactions in different ways and demonstrates that analysis of event-related changes in the amplitude of EEG activity recorded from the human scalp can reveal information about event-related brain processes unavailable using event-related potential measures. Time-varying spectral power in a selected (35- to 43-Hz) gamma frequency band was averaged across trials in two experimental conditions: passive listening and speeded reacting to binaural clicks, forming 40-Hz event-related spectral responses. Factor analysis of between-subject event-related spectral response differences split subjects into two near-equal groups composed of faster- and slower-reacting subjects. In faster-reacting subjects, 40-Hz power peaked near 200 ms and 400 ms poststimulus in the react condition, whereas in slower-reacting subjects, 40-Hz power just before stimulus delivery was larger in the react condition. These group differences were preserved in separate averages of relatively long and short reaction-time epochs for each group. gamma-band (20-60 Hz)-filtered event-related potential response averages did not differ between the two groups or conditions. Because of this and because gamma-band power in the auditory event-related potential is small compared with the EEG, the observed event-related spectral response features must represent gamma-band EEG activity reliably induced by, but not phase-locked to, experimental stimuli or events. PMID:8022783

Effect of pistachio consumption on the modulation of urinary gut microbiota-related metabolites in prediabetic subjects.

Science.gov (United States)

Hernández-Alonso, Pablo; Cañueto, Daniel; Giardina, Simona; Salas-Salvadó, Jordi; Cañellas, Nicolau; Correig, Xavier; Bulló, Mònica

2017-07-01

The specific nutritional composition of nuts could affect different metabolic pathways involved in a broad range of metabolic diseases. We therefore investigated whether chronic consumption of pistachio nuts modifies the urine metabolome in prediabetic subjects. We designed a randomized crossover clinical trial in 39 prediabetic subjects. They consumed a pistachio-supplemented diet (PD, 50% carbohydrates, 33% fat, including 57 g/d of pistachios daily) and a control diet (CD, 55% carbohydrates, 30% fat) for 4 months each, separated by a 2-week wash-out. Nuclear magnetic resonance (NRM) was performed to determine changes in 24-h urine metabolites. Significant changes in urine metabolites according to the different intervention periods were found in uni- and multivariate analysis. Score plot of the first two components of the multilevel partial least squares discriminant analysis (ML-PLS-DA) showed a clear separation of the intervention periods. Three metabolites related with gut microbiota metabolism (i.e., hippurate, p-cresol sulfate and dimethylamine) were found decreased in PD compared with CD (Ppistachio consumption may modulate some urinary metabolites related to gut microbiota metabolism and the TCA cycle; all associated with metabolic derangements associated with insulin resistance and Type 2 diabetes. Copyright © 2017 Elsevier Inc. All rights reserved.

Model theory and modules

CERN Document Server

Prest, M

1988-01-01

In recent years the interplay between model theory and other branches of mathematics has led to many deep and intriguing results. In this, the first book on the topic, the theme is the interplay between model theory and the theory of modules. The book is intended to be a self-contained introduction to the subject and introduces the requisite model theory and module theory as it is needed. Dr Prest develops the basic ideas concerning what can be said about modules using the information which may be expressed in a first-order language. Later chapters discuss stability-theoretic aspects of module

Psychophysical evidence for auditory motion parallax.

Science.gov (United States)

Genzel, Daria; Schutte, Michael; Brimijoin, W Owen; MacNeilage, Paul R; Wiegrebe, Lutz

2018-04-17

Distance is important: From an ecological perspective, knowledge about the distance to either prey or predator is vital. However, the distance of an unknown sound source is particularly difficult to assess, especially in anechoic environments. In vision, changes in perspective resulting from observer motion produce a reliable, consistent, and unambiguous impression of depth known as motion parallax. Here we demonstrate with formal psychophysics that humans can exploit auditory motion parallax, i.e., the change in the dynamic binaural cues elicited by self-motion, to assess the relative depths of two sound sources. Our data show that sensitivity to relative depth is best when subjects move actively; performance deteriorates when subjects are moved by a motion platform or when the sound sources themselves move. This is true even though the dynamic binaural cues elicited by these three types of motion are identical. Our data demonstrate a perceptual strategy to segregate intermittent sound sources in depth and highlight the tight interaction between self-motion and binaural processing that allows assessment of the spatial layout of complex acoustic scenes.

The role of the temporal pole in modulating primitive auditory memory.

Science.gov (United States)

Liu, Zhiliang; Wang, Qian; You, Yu; Yin, Peng; Ding, Hu; Bao, Xiaohan; Yang, Pengcheng; Lu, Hao; Gao, Yayue; Li, Liang

2016-04-21

Primitive auditory memory (PAM), which is recognized as the early point in the chain of the transient auditory memory system, faithfully maintains raw acoustic fine-structure signals for up to 20-30 milliseconds. The neural mechanisms underlying PAM have not been reported in the literature. Previous anatomical, brain-imaging, and neurophysiological studies have suggested that the temporal pole (TP), part of the parahippocampal region in the transitional area between perirhinal cortex and superior/inferior temporal gyri, is involved in auditory memories. This study investigated whether the TP plays a role in mediating/modulating PAM. The longest interaural interval (the interaural-delay threshold) for detecting a break in interaural correlation (BIC) embedded in interaurally correlated wideband noises was used to indicate the temporal preservation of PAM and examined in both healthy listeners and patients receiving unilateral anterior temporal lobectomy (ATL, centered on the TP) for treating their temporal lobe epilepsy (TLE). The results showed that patients with ATL were still able to detect the BIC even when an interaural interval was introduced, regardless of which ear was the leading one. However, in patient participants, the group-mean interaural-delay threshold for detecting the BIC under the contralateral-ear-leading (relative to the side of ATL) condition was significantly shorter than that under the ipsilateral-ear-leading condition. The results suggest that although the TP is not essential for integrating binaural signals and mediating the PAM, it plays a role in top-down modulating the PAM of raw acoustic fine-structure signals from the contralateral ear. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Classes of modules

CERN Document Server

Dauns, John

2006-01-01

Because traditional ring theory places restrictive hypotheses on all submodules of a module, its results apply only to small classes of already well understood examples. Often, modules with infinite Goldie dimension have finite-type dimension, making them amenable to use with type dimension, but not Goldie dimension. By working with natural classes and type submodules (TS), Classes of Modules develops the foundations and tools for the next generation of ring and module theory. It shows how to achieve positive results by placing restrictive hypotheses on a small subset of the complement submodules, Furthermore, it explains the existence of various direct sum decompositions merely as special cases of type direct sum decompositions. Carefully developing the foundations of the subject, the authors begin by providing background on the terminology and introducing the different module classes. The modules classes consist of torsion, torsion-free, s[M], natural, and prenatural. They expand the discussion by exploring...

Spectrotemporal Modulation Detection and Speech Perception by Cochlear Implant Users.

Science.gov (United States)

Won, Jong Ho; Moon, Il Joon; Jin, Sunhwa; Park, Heesung; Woo, Jihwan; Cho, Yang-Sun; Chung, Won-Ho; Hong, Sung Hwa

2015-01-01

Spectrotemporal modulation (STM) detection performance was examined for cochlear implant (CI) users. The test involved discriminating between an unmodulated steady noise and a modulated stimulus. The modulated stimulus presents frequency modulation patterns that change in frequency over time. In order to examine STM detection performance for different modulation conditions, two different temporal modulation rates (5 and 10 Hz) and three different spectral modulation densities (0.5, 1.0, and 2.0 cycles/octave) were employed, producing a total 6 different STM stimulus conditions. In order to explore how electric hearing constrains STM sensitivity for CI users differently from acoustic hearing, normal-hearing (NH) and hearing-impaired (HI) listeners were also tested on the same tasks. STM detection performance was best in NH subjects, followed by HI subjects. On average, CI subjects showed poorest performance, but some CI subjects showed high levels of STM detection performance that was comparable to acoustic hearing. Significant correlations were found between STM detection performance and speech identification performance in quiet and in noise. In order to understand the relative contribution of spectral and temporal modulation cues to speech perception abilities for CI users, spectral and temporal modulation detection was performed separately and related to STM detection and speech perception performance. The results suggest that that slow spectral modulation rather than slow temporal modulation may be important for determining speech perception capabilities for CI users. Lastly, test-retest reliability for STM detection was good with no learning. The present study demonstrates that STM detection may be a useful tool to evaluate the ability of CI sound processing strategies to deliver clinically pertinent acoustic modulation information.

Human Factors Engineering Bibliographic Series. Volume 5, 1967 Literature

Science.gov (United States)

1976-03-01

Continuous record2 of pvIiss :ate and the total number of I-*art beats can now te obtained over long periods a! tins. The different devices and the choice of...In *no ear. At least one shovs no fusioo of a binaurally presented sigral when the part of the signal in the ear recelving interference I Is...orestntina 4iignls binAurally with complete masking In on. ear. The stili oe pure tones, and a subject manaulates teloudness of the signal In the umnsked car

Chaotic Darcy-Brinkman convection in a fluid saturated porous layer subjected to gravity modulation

Directory of Open Access Journals (Sweden)

Moli Zhao

2018-06-01

Full Text Available On the basis of Darcy-Brinkman model, the chaotic convection in a couple stress fluid saturated porous media under gravity modulation is investigated using the nonlinear stability analyses. The transition from steady convection to chaos is analysed with the effect of Darcy-Brinkman couple stress parameter and the gravity modulation. The results show that the chaotic behavior is connected with the critical value of Rayleigh number which is dependent upon the oscillation frequency and the Darcy-Brinkman couple stress parameter. If the oscillation frequency Ω is not zero, the Rayleigh number value R of the chaotic behavior increases with the increase of the Darcy-Brinkman couple stress parameter. The Darcy-Brinkman couple stress parameter and the gravity modulation decrease the rate of heat transfer. Keywords: Darcy-Brinkman model, Gravity modulation, Nonlinear stability, Chaotic convection

Evidence of successful modulation of brain activation and subjective experience during reappraisal of negative emotion in unmedicated depression.

Science.gov (United States)

Dillon, Daniel Gerard; Pizzagalli, Diego Andrea

2013-05-30

Functional magnetic resonance imaging (fMRI) was used to examine cognitive regulation of negative emotion in 12 unmedicated patients with major depressive disorder (MDD) and 24 controls. The participants used reappraisal to increase (real condition) and reduce (photo condition) the personal relevance of negative and neutral pictures during fMRI as valence ratings were collected; passive viewing (look condition) served as a baseline. Reappraisal was not strongly affected by MDD. Ratings indicated that both groups successfully reappraised negative emotional experience. Both groups also showed better memory for negative vs. neutral pictures 2 weeks later. Across groups, increased brain activation was observed on negative/real vs. negative/look and negative/photo trials in left dorsolateral prefrontal cortex (DLPFC), rostral anterior cingulate, left parietal cortex, caudate, and right amygdala. Depressive severity was inversely correlated with activation modulation in the left DLPFC, right amygdala, and right cerebellum during negative reappraisal. The lack of group differences suggests that depressed adults can modulate the brain activation and subjective experience elicited by negative pictures when given clear instructions. However, the negative relationship between depression severity and effects of reappraisal on brain activation indicates that group differences may be detectable in larger samples of more severely depressed participants. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Auditory middle latency responses differ in right- and left-handed subjects: an evaluation through topographic brain mapping.

Science.gov (United States)

Mohebbi, Mehrnaz; Mahmoudian, Saeid; Alborzi, Marzieh Sharifian; Najafi-Koopaie, Mojtaba; Farahani, Ehsan Darestani; Farhadi, Mohammad

2014-09-01

To investigate the association of handedness with auditory middle latency responses (AMLRs) using topographic brain mapping by comparing amplitudes and latencies in frontocentral and hemispheric regions of interest (ROIs). The study included 44 healthy subjects with normal hearing (22 left handed and 22 right handed). AMLRs were recorded from 29 scalp electrodes in response to binaural 4-kHz tone bursts. Frontocentral ROI comparisons revealed that Pa and Pb amplitudes were significantly larger in the left-handed than the right-handed group. Topographic brain maps showed different distributions in AMLR components between the two groups. In hemispheric comparisons, Pa amplitude differed significantly across groups. A left-hemisphere emphasis of Pa was found in the right-handed group but not in the left-handed group. This study provides evidence that handedness is associated with AMLR components in frontocentral and hemispheric ROI. Handedness should be considered an essential factor in the clinical or experimental use of AMLRs.

Fine-structure processing, frequency selectivity and speech perception in hearing-impaired listeners

DEFF Research Database (Denmark)

Strelcyk, Olaf; Dau, Torsten

2008-01-01

Hearing-impaired people often experience great difficulty with speech communication when background noise is present, even if reduced audibility has been compensated for. Other impairment factors must be involved. In order to minimize confounding effects, the subjects participating in this study...... consisted of groups with homogeneous, symmetric audiograms. The perceptual listening experiments assessed the intelligibility of full-spectrum as well as low-pass filtered speech in the presence of stationary and fluctuating interferers, the individual's frequency selectivity and the integrity of temporal...... modulation were obtained. In addition, these binaural and monaural thresholds were measured in a stationary background noise in order to assess the persistence of the fine-structure processing to interfering noise. Apart from elevated speech reception thresholds, the hearing impaired listeners showed poorer...

Attention modulates visual size adaptation.

Science.gov (United States)

Kreutzer, Sylvia; Fink, Gereon R; Weidner, Ralph

2015-01-01

The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance detection task. When attention was directed toward the small as compared to the large adapter, the perceived size of the subsequent target was significantly increased. Data suggest that different size adaptation effects can be induced by one and the same stimulus depending on the current allocation of attention. This indicates that size adaptation is subject to attentional modulation. These findings are in line with previous research showing that transient as well as sustained attention modulates visual features, such as contrast sensitivity and spatial frequency, and influences adaptation in other contexts, such as motion adaptation (Alais & Blake, 1999; Lankheet & Verstraten, 1995). Based on a recently suggested model (Pooresmaeili, Arrighi, Biagi, & Morrone, 2013), according to which perceptual adaptation is based on local excitation and inhibition in V1, we conclude that guiding attention can boost these local processes in one or the other direction by increasing the weight of the attended adapter. In sum, perceptual adaptation, although reflected in changes of neural activity at early levels (as shown in the aforementioned study), is nevertheless subject to higher-order modulation.

Single channel speech enhancement in the modulation domain: New insights in the modulation channel selection framework

DEFF Research Database (Denmark)

Boldt, Jesper B.; Bertelsen, Andreas Thelander; Gran, Fredrik

2015-01-01

Recently, the ideal binary mask has been introduced in the modulation domain by extending the ideal channel selection method to modulation channel selection [1]. This new method shows substantial improvement in speech intelligibility but less than its predecessor despite the higher complexity. Here......, we extend the previous finding from [1] and provide a more direct comparison of binary masking in the modulation domain with binary masking in the time-frequency domain. Subjective and objective evaluations are performed and provide additional insight into modulation domain processing....

Virtual Visual Effect of Hospital Waiting Room on Pain Modulation in Healthy Subjects and Patients with Chronic Migraine

Directory of Open Access Journals (Sweden)

Marina de Tommaso

2013-01-01

Full Text Available Environmental context has an important impact on health and well being. We aimed to test the effects of a visual distraction induced by classical hospital waiting room (RH versus an ideal room with a sea view (IH, both represented in virtual reality (VR, on subjective sensation and cortical responses induced by painful laser stimuli (LEPs in healthy volunteers and patients with chronic migraine (CM. Sixteen CM and 16 controls underwent 62 channels LEPs from the right hand, during a fully immersive VR experience, where two types of waiting rooms were simulated. The RH simulated a classical hospital waiting room while the IH represented a room with sea viewing. CM patients showed a reduction of laser pain rating and vertex LEPs during the IH vision. The sLORETA analysis confirmed that in CM patients the two VR simulations induced a different modulation of bilateral parietal cortical areas (precuneus and superior parietal lobe, and superior frontal and cingulate girus, in respect to controls. The architectural context may interfere with pain perception, depending upon the status of subject. Many variables may change patients’ outcome and support the use of VR technology to test the best conditions for their management.

Suggestibility and suggestive modulation of the Stroop effect.

Science.gov (United States)

Kirsch, Irving

2011-06-01

Although the induction of a hypnotic state does not seem necessary for suggestive modulation of the Stroop effect, this important phenomenon has seemed to be dependent on the subject's level of hypnotic suggestibility. Raz and Campbell's (2011) study indicates that suggestion can modulate the Stroop effect substantially in very low suggestible subjects, as well as in those who are highly suggestible. This finding casts doubt on the presumed mechanism by which suggestive modulation is brought about. Research aimed at uncovering the means by which low suggestible individuals are able to modulate the Stroop effect would be welcome, as would assessment of this effect in moderately suggestible people. Copyright © 2010 Elsevier Inc. All rights reserved.

Foot reflexology can increase vagal modulation, decrease sympathetic modulation, and lower blood pressure in healthy subjects and patients with coronary artery disease.

Science.gov (United States)

Lu, Wan-An; Chen, Gau-Yang; Kuo, Cheng-Deng

2011-01-01

Complementary and alternative medicine (CAM) has long been used by people to postpone the aging process and to reverse disease progression. Reflexology is a CAM method that involves massage to reflex areas in the feet and hands. This study investigated the effect of foot reflexology (FR) on the autonomic nervous modulation in patients with coronary artery disease (CAD) by using heart rate variability analysis. Seventeen people with angiographically patent coronary arteries and 20 patients with CAD scheduled for coronary artery bypass graft surgery were recruited as the control and CAD groups, respectively. The normalized high-frequency power (nHFP) was used as the index of vagal modulation and the normalized very low-frequency power (nVLFP) as the index of vagal withdrawal and renin-angiotensin modulation. In both control and CAD groups, the nHFP was increased significantly whereas the nVLFP was decreased significantly 30 and 60 minutes after FR, as compared with those before FR. The systolic, diastolic, mean arterial, and pulse pressures were significantly decreased after FR in both groups of participants. In the CAD group, the percentage change in heart rate 30 and 60 minutes after FR was smaller than that in the control, and the percentage change in nVLFP 60 minutes after FR was smaller than that in the control. In conclusion, a higher vagal modulation, lower sympathetic modulation, and lower blood pressure can be observed following 60 minutes of FR in both controls and CAD patients. The magnitude of change in the autonomic nervous modulation in CAD patients was slightly smaller than that in the controls. FR may be used as an efficient adjunct to the therapeutic regimen to increase the vagal modulation and decrease blood pressure in both healthy people and CAD patients.

Plastic modulation of PTSD resting-state networks and subjective wellbeing by EEG neurofeedback.

Science.gov (United States)

Kluetsch, R C; Ros, T; Théberge, J; Frewen, P A; Calhoun, V D; Schmahl, C; Jetly, R; Lanius, R A

2014-08-01

Electroencephalographic (EEG) neurofeedback training has been shown to produce plastic modulations in salience network and default mode network functional connectivity in healthy individuals. In this study, we investigated whether a single session of neurofeedback training aimed at the voluntary reduction of alpha rhythm (8-12 Hz) amplitude would be related to differences in EEG network oscillations, functional MRI (fMRI) connectivity, and subjective measures of state anxiety and arousal in a group of individuals with post-traumatic stress disorder (PTSD). Twenty-one individuals with PTSD related to childhood abuse underwent 30 min of EEG neurofeedback training preceded and followed by a resting-state fMRI scan. Alpha desynchronizing neurofeedback was associated with decreased alpha amplitude during training, followed by a significant increase ('rebound') in resting-state alpha synchronization. This rebound was linked to increased calmness, greater salience network connectivity with the right insula, and enhanced default mode network connectivity with bilateral posterior cingulate, right middle frontal gyrus, and left medial prefrontal cortex. Our study represents a first step in elucidating the potential neurobehavioural mechanisms mediating the effects of neurofeedback treatment on regulatory systems in PTSD. Moreover, it documents for the first time a spontaneous EEG 'rebound' after neurofeedback, pointing to homeostatic/compensatory mechanisms operating in the brain. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Optimizing nasal potential difference analysis for CFTR modulator development: assessment of ivacaftor in CF subjects with the G551D-CFTR mutation.

Directory of Open Access Journals (Sweden)

Steven M Rowe

Full Text Available Nasal potential difference (NPD is used as a biomarker of the cystic fibrosis transmembrane conductance regulator (CFTR and epithelial sodium channel (ENaC activity. We evaluated methods to detect changes in chloride and sodium transport by NPD based on a secondary analysis of a Phase II CFTR-modulator study. Thirty-nine subjects with CF who also had the G551D-CFTR mutation were randomized to receive ivacaftor (Kalydeco™; also known as VX-770 in four doses or placebo twice daily for at least 14 days. All data were analyzed by a single investigator who was blinded to treatment assignment. We compared three analysis methods to determine the best approach to quantify changes in chloride and sodium transport: (1 the average of both nostrils; (2 the most-polarized nostril at each visit; and (3 the most-polarized nostril at screening carried forward. Parameters of ion transport included the PD change with zero chloride plus isoproterenol (CFTR activity, the basal PD, Ringer's PD, and change in PD with amiloride (measurements of ENaC activity, and the delta NPD (measuring CFTR and ENaC activity. The average and most-polarized nostril at each visit were most sensitive to changes in chloride and sodium transport, whereas the most-polarized nostril at screening carried forward was less discriminatory. Based on our findings, NPD studies should assess both nostrils rather than a single nostril. We also found that changes in CFTR activity were more readily detected than changes in ENaC activity, and that rigorous standardization was associated with relatively good within-subject reproducibility in placebo-treated subjects (± 2.8 mV. Therefore, we have confirmed an assay of reasonable reproducibility for detecting chloride-transport improvements in response to CFTR modulation.

Culturally Relevant Human Subjects Protection Training: A Case Study in Community-Engaged Research in the United States.

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Kue, Jennifer; Szalacha, Laura A; Happ, Mary Beth; Crisp, Abigail L; Menon, Usha

2018-02-01

Non-academic members of research teams, such as community members, can perceive traditional human subjects protection training as lacking in cultural relevance. We present a case exemplar of the development of a human subjects protection training for research staff with limited English proficiency and/or no or limited research experience. Seven modules were adapted for language, cultural examples, etc., from the standard Collaborative Institutional Training Initiative (CITI) human subjects protection training. Non-academic research staff completed a day-long training in human subjects protection (six modules) and our research protocol (one module). We assessed comprehension of content with PowerPoint slides and module quizzes. All participants successfully passed each module quiz with ≥ 80% correct. Questions answered incorrectly were discussed before proceeding to the next module. To meet the increasing demand for collaborative community-engaged research with underserved minority populations, human subjects protection training protocols can be adapted successfully to reflect real-world situations and provide culturally relevant materials to help non-academic research staff better understand the importance and necessity of research ethics.

Motor modules during adaptation to walking in a powered ankle exoskeleton.

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Jacobs, Daniel A; Koller, Jeffrey R; Steele, Katherine M; Ferris, Daniel P

2018-01-03

Modules of muscle recruitment can be extracted from electromyography (EMG) during motions, such as walking, running, and swimming, to identify key features of muscle coordination. These features may provide insight into gait adaptation as a result of powered assistance. The aim of this study was to investigate the changes (module size, module timing and weighting patterns) of surface EMG data during assisted and unassisted walking in an powered, myoelectric, ankle-foot orthosis (ankle exoskeleton). Eight healthy subjects wore bilateral ankle exoskeletons and walked at 1.2 m/s on a treadmill. In three training sessions, subjects walked for 40 min in two conditions: unpowered (10 min) and powered (30 min). During each session, we extracted modules of muscle recruitment via nonnegative matrix factorization (NNMF) from the surface EMG signals of ten muscles in the lower limb. We evaluated reconstruction quality for each muscle individually using R 2 and normalized root mean squared error (NRMSE). We hypothesized that the number of modules needed to reconstruct muscle data would be the same between conditions and that there would be greater similarity in module timings than weightings. Across subjects, we found that six modules were sufficient to reconstruct the muscle data for both conditions, suggesting that the number of modules was preserved. The similarity of module timings and weightings between conditions was greater then random chance, indicating that muscle coordination was also preserved. Motor adaptation during walking in the exoskeleton was dominated by changes in the module timings rather than module weightings. The segment number and the session number were significant fixed effects in a linear mixed-effect model for the increase in R 2 with time. Our results show that subjects walking in a exoskeleton preserved the number of modules and the coordination of muscles within the modules across conditions. Training (motor adaptation within the session and

EEG activity as an objective measure of cognitive load during effortful listening: A study on pediatric subjects with bilateral, asymmetric sensorineural hearing loss.

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Marsella, Pasquale; Scorpecci, Alessandro; Cartocci, Giulia; Giannantonio, Sara; Maglione, Anton Giulio; Venuti, Isotta; Brizi, Ambra; Babiloni, Fabio

2017-08-01

Deaf subjects with hearing aids or cochlear implants generally find it challenging to understand speech in noisy environments where a great deal of listening effort and cognitive load are invested. In prelingually deaf children, such difficulties may have detrimental consequences on the learning process and, later in life, on academic performance. Despite the importance of such a topic, currently, there is no validated test for the assessment of cognitive load during audiological tasks. Recently, alpha and theta EEG rhythm variations in the parietal and frontal areas, respectively, have been used as indicators of cognitive load in adult subjects. The aim of the present study was to investigate, by means of EEG, the cognitive load of pediatric subjects affected by asymmetric sensorineural hearing loss as they were engaged in a speech-in-noise identification task. Seven children (4F and 3M, age range = 8-16 years) affected by asymmetric sensorineural hearing loss (i.e. profound degree on one side, mild-to-severe degree on the other side) and using a hearing aid only in their better ear, were included in the study. All of them underwent EEG recording during a speech-in-noise identification task: the experimental conditions were quiet, binaural noise, noise to the better hearing ear and noise to the poorer hearing ear. The subjects' Speech Recognition Thresholds (SRT) were also measured in each test condition. The primary outcome measures were: frontal EEG Power Spectral Density (PSD) in the theta band and parietal EEG PSD in the alpha band, as assessed before stimulus (word) onset. No statistically significant differences were noted among frontal theta power levels in the four test conditions. However, parietal alpha power levels were significantly higher in the "binaural noise" and in the "noise to worse hearing ear" conditions than in the "quiet" and "noise to better hearing ear" conditions (p cognitive load during effortful listening. Significantly higher

Task-induced frequency modulation features for brain-computer interfacing.

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Jayaram, Vinay; Hohmann, Matthias; Just, Jennifer; Schölkopf, Bernhard; Grosse-Wentrup, Moritz

2017-10-01

Task-induced amplitude modulation of neural oscillations is routinely used in brain-computer interfaces (BCIs) for decoding subjects' intents, and underlies some of the most robust and common methods in the field, such as common spatial patterns and Riemannian geometry. While there has been some interest in phase-related features for classification, both techniques usually presuppose that the frequencies of neural oscillations remain stable across various tasks. We investigate here whether features based on task-induced modulation of the frequency of neural oscillations enable decoding of subjects' intents with an accuracy comparable to task-induced amplitude modulation. We compare cross-validated classification accuracies using the amplitude and frequency modulated features, as well as a joint feature space, across subjects in various paradigms and pre-processing conditions. We show results with a motor imagery task, a cognitive task, and also preliminary results in patients with amyotrophic lateral sclerosis (ALS), as well as using common spatial patterns and Laplacian filtering. The frequency features alone do not significantly out-perform traditional amplitude modulation features, and in some cases perform significantly worse. However, across both tasks and pre-processing in healthy subjects the joint space significantly out-performs either the frequency or amplitude features alone. This result only does not hold for ALS patients, for whom the dataset is of insufficient size to draw any statistically significant conclusions. Task-induced frequency modulation is robust and straight forward to compute, and increases performance when added to standard amplitude modulation features across paradigms. This allows more information to be extracted from the EEG signal cheaply and can be used throughout the field of BCIs.

The combined effects of forward masking by noise and high click rate on monaural and binaural human auditory nerve and brainstem potentials.

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Pratt, Hillel; Polyakov, Andrey; Bleich, Naomi; Mittelman, Naomi

2004-07-01

To study effects of forward masking and rapid stimulation on human monaurally- and binaurally-evoked brainstem potentials and suggest their relation to synaptic fatigue and recovery and to neuronal action potential refractoriness. Auditory brainstem evoked potentials (ABEPs) were recorded from 12 normally- and symmetrically hearing adults, in response to each click (50 dB nHL, condensation and rarefaction) in a train of nine, with an inter-click interval of 11 ms, that followed a white noise burst of 100 ms duration (50 dB nHL). Sequences of white noise and click train were repeated at a rate of 2.89 s(-1). The interval between noise and first click in the train was 2, 11, 22, 44, 66 or 88 ms in different runs. ABEPs were averaged (8000 repetitions) using a dwell time of 25 micros/address/channel. The binaural interaction components (BICs) of ABEPs were derived and the single, centrally located equivalent dipoles of ABEP waves I and V and of the BIC major wave were estimated. The latencies of dipoles I and V of ABEP, their inter-dipole interval and the dipole magnitude of component V were significantly affected by the interval between noise and clicks and by the serial position of the click in the train. The latency and dipole magnitude of the major BIC component were significantly affected by the interval between noise and clicks. Interval from noise and the click's serial position in the train interacted to affect dipole V latency, dipole V magnitude, BIC latencies and the V-I inter-dipole latency difference. Most of the effects were fully apparent by the first few clicks in the train, and the trend (increase or decrease) was affected by the interval between noise and clicks. The changes in latency and magnitude of ABEP and BIC components with advancing position in the click train and the interactions of click position in the train with the intervals from noise indicate an interaction of fatigue and recovery, compatible with synaptic depletion and replenishing

Spectro-temporal cues enhance modulation sensitivity in cochlear implant users.

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Zheng, Yi; Escabí, Monty; Litovsky, Ruth Y

2017-08-01

Although speech understanding is highly variable amongst cochlear implants (CIs) subjects, the remarkably high speech recognition performance of many CI users is unexpected and not well understood. Numerous factors, including neural health and degradation of the spectral information in the speech signal of CIs, likely contribute to speech understanding. We studied the ability to use spectro-temporal modulations, which may be critical for speech understanding and discrimination, and hypothesize that CI users adopt a different perceptual strategy than normal-hearing (NH) individuals, whereby they rely more heavily on joint spectro-temporal cues to enhance detection of auditory cues. Modulation detection sensitivity was studied in CI users and NH subjects using broadband "ripple" stimuli that were modulated spectrally, temporally, or jointly, i.e., spectro-temporally. The spectro-temporal modulation transfer functions of CI users and NH subjects was decomposed into spectral and temporal dimensions and compared to those subjects' spectral-only and temporal-only modulation transfer functions. In CI users, the joint spectro-temporal sensitivity was better than that predicted by spectral-only and temporal-only sensitivity, indicating a heightened spectro-temporal sensitivity. Such an enhancement through the combined integration of spectral and temporal cues was not observed in NH subjects. The unique use of spectro-temporal cues by CI patients can yield benefits for use of cues that are important for speech understanding. This finding has implications for developing sound processing strategies that may rely on joint spectro-temporal modulations to improve speech comprehension of CI users, and the findings of this study may be valuable for developing clinical assessment tools to optimize CI processor performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Sound localization in common vampire bats: Acuity and use of the binaural time cue by a small mammal

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Heffner, Rickye S.; Koay, Gimseong; Heffner, Henry E.

2015-01-01

Passive sound-localization acuity and the ability to use binaural time and intensity cues were determined for the common vampire bat (Desmodus rotundus). The bats were tested using a conditioned suppression/avoidance procedure in which they drank defibrinated blood from a spout in the presence of sounds from their right, but stopped drinking (i.e., broke contact with the spout) whenever a sound came from their left, thereby avoiding a mild shock. The mean minimum audible angle for three bats for a 100-ms noise burst was 13.1°—within the range of thresholds for other bats and near the mean for mammals. Common vampire bats readily localized pure tones of 20 kHz and higher, indicating they could use interaural intensity-differences. They could also localize pure tones of 5 kHz and lower, thereby demonstrating the use of interaural time-differences, despite their very small maximum interaural distance of 60 μs. A comparison of the use of locus cues among mammals suggests several implications for the evolution of sound localization and its underlying anatomical and physiological mechanisms. PMID:25618037

Rate modulation detection thresholds for cochlear implant users.

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Brochier, Tim; McKay, Colette; McDermott, Hugh

2018-02-01

The perception of temporal amplitude modulations is critical for speech understanding by cochlear implant (CI) users. The present study compared the ability of CI users to detect sinusoidal modulations of the electrical stimulation rate and current level, at different presentation levels (80% and 40% of the dynamic range) and modulation frequencies (10 and 100 Hz). Rate modulation detection thresholds (RMDTs) and amplitude modulation detection thresholds (AMDTs) were measured and compared to assess whether there was a perceptual advantage to either modulation method. Both RMDTs and AMDTs improved with increasing presentation level and decreasing modulation frequency. RMDTs and AMDTs were correlated, indicating that a common processing mechanism may underlie the perception of rate modulation and amplitude modulation, or that some subject-dependent factors affect both types of modulation detection.

Hypnosis modulates behavioural measures and subjective ratings about external and internal awareness.

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Demertzi, Athena; Vanhaudenhuyse, Audrey; Noirhomme, Quentin; Faymonville, Marie-Elisabeth; Laureys, Steven

2015-12-01

In altered subjective states, the behavioural quantification of external and internal awareness remains challenging due to the need for reports on the subjects' behalf. With the aim to characterize the behavioural counterpart of external and internal awareness in a modified subjective condition, we used hypnosis during which subjects remain fully responsive. Eleven right-handed subjects reached a satisfactory level of hypnotisability as evidenced by subjective reports on arousal, absorption and dissociation. Compared to normal wakefulness, in hypnosis (a) participants' self-ratings for internal awareness increased and self-ratings for external awareness decreased, (b) the two awareness components tended to anticorrelate less and the switches between external and internal awareness self-ratings were less frequent, and (c) participants' reaction times were higher and lapses in key presses were more frequent. The identified imbalance between the two components of awareness is considered as of functional relevance to subjective (meta)cognition, possibly mediated by allocated attentional properties brought about by hypnosis. Our results highlight the presence of a cognitive counterpart in resting state, indicate that the modified contents of awareness are measurable behaviourally, and provide leverage for investigations of more challenging altered conscious states, such as anaesthesia, sleep and disorders of consciousness. Copyright © 2015 Elsevier Ltd. All rights reserved.

Accounting for binaural detection as a function of masker interaural correlation: effects of center frequency and bandwidth.

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Bernstein, Leslie R; Trahiotis, Constantine

2014-12-01

Binaural detection was measured as a function of the center frequency, bandwidth, and interaural correlation of masking noise. Thresholds were obtained for 500-Hz or 125-Hz Sπ tonal signals and for the latter stimuli (noise or signal-plus-noise) transposed to 4 kHz. A primary goal was assessment of the generality of van der Heijden and Trahiotis' [J. Acoust. Soc. Am. 101, 1019-1022 (1997)] hypothesis that thresholds could be accounted for by the "additive" masking effects of the underlying No and Nπ components of a masker having an interaural correlation of ρ. Results indicated that (1) the overall patterning of the data depended neither upon center frequency nor whether information was conveyed via the waveform or by its envelope; (2) thresholds for transposed stimuli improved relative to their low-frequency counterparts as bandwidth of the masker was increased; (3) the additivity approach accounted well for the data across stimulus conditions but consistently overestimated MLDs, especially for narrowband maskers; (4) a quantitative approach explicitly taking into account the distributions of time-varying ITD-based lateral positions produced by masker-alone and signal-plus-masker waveforms proved more successful, albeit while employing a larger set of assumptions, parameters, and computational complexity.

Medication overuse reinstates conditioned pain modulation in women with migraine.

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Guy, Nathalie; Voisin, Daniel; Mulliez, Aurélien; Clavelou, Pierre; Dallel, Radhouane

2018-05-01

Background This study investigated the effects of medication overuse and withdrawal on modulation of pain processing in women with migraine. Temporal summation of laser-evoked thermal pain was used to measure the effects of conditioned pain modulation. Methods 36 female participants (12 healthy volunteers, 12 with episodic migraine and 12 with medication overuse headache) were included in a two session protocol. Medication overuse headache subjects were also tested three weeks after medication overuse headache withdrawal. Mechanical and laser-evoked thermal pain thresholds were measured on the back of the non-dominant hand where, later, temporal summation of laser-evoked thermal pain to repetitive thermal stimuli was elicited for 30 min, at an intensity producing moderate pain. Between the 10 th and 20 th minutes, the contralateral foot was immersed into a water bath at a not painful (30℃) or painfully cold (8℃; conditioned pain modulation) temperature. Results Episodic migraine, medication overuse headache and medication overuse headache withdrawal were associated with an increase in extracephalic temporal summation of laser-evoked thermal pain as compared to healthy volunteer subjects, while there was no alteration of laser-evoked thermal and mechanical extracephalic pain thresholds in these subjects. Conditioned pain modulation was highly efficient in temporal summation of laser-evoked thermal pain in healthy volunteer subjects, with a solid post-effect (reduction of pain). Conditioned pain modulation was still present, but reduced, in episodic migraine. By contrast, conditioned pain modulation was normal in medication overuse headache and strongly reduced in medication overuse headache withdrawal. Furthermore, in medication overuse headache withdrawal, the post-effect was no longer a decrease, but a facilitation of pain. Conclusions These data show that a decrease in conditioned pain modulation does not underlie medication overuse headache in women. On

Medio-lateral postural instability in subjects with tinnitus

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Zoi eKapoula

2011-05-01

Full Text Available Background: Many patients show modulation of tinnitus by gaze, jaw or neck movements, reflecting abnormal sensorimotor integration and interaction between various inputs. Postural control is based on multi-sensory integration (visual, vestibular, somatosensory, and oculomotor and indeed there is now evidence that posture can also be influenced by sound. Perhaps tinnitus influences posture similarly to external sound. This study examines the quality of postural performance in quiet stance in patients with modulated tinnitus.Methods: Twenty-three patients with highly modulated tinnitus were selected in the ENT service. Twelve reported exclusively or predominately left tinnitus, eight right and three bilateral. Eighteen control subjects were also tested. Subjects were asked to fixate a target at 40cm for 51s; posturography was performed with the platform (Technoconcept, 40Hz for both the eyes open and eyes closed conditions.Results: For both conditions, tinnitus subjects showed abnormally high lateral body sway (SDx. This was corroborated by fast Fourrier Transformation (FFTx and wavelet analysis. For patients with left tinnitus only, medio-lateral sway increased significantly when looking away from the center. Conclusions: Similarly to external sound stimulation, tinnitus could influence lateral sway by activating attention shift, and perhaps vestibular responses. Poor integration of sensorimotor signals is another possibility. Such abnormalities would be accentuated in left tinnitus because of the importance of the right cerebral cortex in processing both auditory-tinnitus and attention.

Spectro-temporal cues enhance modulation sensitivity in cochlear implant users

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Zheng, Yi; Escabí, Monty; Litovsky, Ruth Y.

2018-01-01

Although speech understanding is highly variable amongst cochlear implants (CIs) subjects, the remarkably high speech recognition performance of many CI users is unexpected and not well understood. Numerous factors, including neural health and degradation of the spectral information in the speech signal of CIs, likely contribute to speech understanding. We studied the ability to use spectro-temporal modulations, which may be critical for speech understanding and discrimination, and hypothesize that CI users adopt a different perceptual strategy than normal-hearing (NH) individuals, whereby they rely more heavily on joint spectro-temporal cues to enhance detection of auditory cues. Modulation detection sensitivity was studied in CI users and NH subjects using broadband “ripple” stimuli that were modulated spectrally, temporally, or jointly, i.e., spectro-temporally. The spectro-temporal modulation transfer functions of CI users and NH subjects was decomposed into spectral and temporal dimensions and compared to those subjects’ spectral-only and temporal-only modulation transfer functions. In CI users, the joint spectro-temporal sensitivity was better than that predicted by spectral-only and temporal-only sensitivity, indicating a heightened spectro-temporal sensitivity. Such an enhancement through the combined integration of spectral and temporal cues was not observed in NH subjects. The unique use of spectro-temporal cues by CI patients can yield benefits for use of cues that are important for speech understanding. This finding has implications for developing sound processing strategies that may rely on joint spectro-temporal modulations to improve speech comprehension of CI users, and the findings of this study may be valuable for developing clinical assessment tools to optimize CI processor performance. PMID:28601530

Dopaminergic Modulation of Decision Making and Subjective Well-Being.

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Rutledge, Robb B; Skandali, Nikolina; Dayan, Peter; Dolan, Raymond J

2015-07-08

The neuromodulator dopamine has a well established role in reporting appetitive prediction errors that are widely considered in terms of learning. However, across a wide variety of contexts, both phasic and tonic aspects of dopamine are likely to exert more immediate effects that have been less well characterized. Of particular interest is dopamine's influence on economic risk taking and on subjective well-being, a quantity known to be substantially affected by prediction errors resulting from the outcomes of risky choices. By boosting dopamine levels using levodopa (l-DOPA) as human subjects made economic decisions and repeatedly reported their momentary happiness, we show here an effect on both choices and happiness. Boosting dopamine levels increased the number of risky options chosen in trials involving potential gains but not trials involving potential losses. This effect could be better captured as increased Pavlovian approach in an approach-avoidance decision model than as a change in risk preferences within an established prospect theory model. Boosting dopamine also increased happiness resulting from some rewards. Our findings thus identify specific novel influences of dopamine on decision making and emotion that are distinct from its established role in learning. Copyright © 2015 Rutledge et al.

Dopaminergic Modulation of Decision Making and Subjective Well-Being

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Skandali, Nikolina; Dayan, Peter; Dolan, Raymond J.

2015-01-01

The neuromodulator dopamine has a well established role in reporting appetitive prediction errors that are widely considered in terms of learning. However, across a wide variety of contexts, both phasic and tonic aspects of dopamine are likely to exert more immediate effects that have been less well characterized. Of particular interest is dopamine's influence on economic risk taking and on subjective well-being, a quantity known to be substantially affected by prediction errors resulting from the outcomes of risky choices. By boosting dopamine levels using levodopa (l-DOPA) as human subjects made economic decisions and repeatedly reported their momentary happiness, we show here an effect on both choices and happiness. Boosting dopamine levels increased the number of risky options chosen in trials involving potential gains but not trials involving potential losses. This effect could be better captured as increased Pavlovian approach in an approach–avoidance decision model than as a change in risk preferences within an established prospect theory model. Boosting dopamine also increased happiness resulting from some rewards. Our findings thus identify specific novel influences of dopamine on decision making and emotion that are distinct from its established role in learning. PMID:26156984

Comparison of Caffeine and d-amphetamine in Cocaine-Dependent Subjects: Differential Outcomes on Subjective and Cardiovascular Effects, Reward Learning, and Salivary Paraxanthine.

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Lane, Scott D; Green, Charles E; Schmitz, Joy M; Rathnayaka, Nuvan; Fang, Wendy B; Ferré, Sergi; Moeller, F Gerard

2014-01-01

Due to indirect modulation of dopamine transmission, adenosine receptor antagonists may be useful in either treating cocaine use or improving disrupted cognitive-behavioral functions associated with chronic cocaine use. To compare and contrast the stimulant effects of adenosine antagonism to direct dopamine stimulation, we administered 150 mg and 300 mg caffeine, 20 mg amphetamine, and placebo to cocaine-dependent vs. healthy control subjects, matched on moderate caffeine use. Data were obtained on measures of cardiovascular effects, subjective drug effects (ARCI, VAS, DEQ), and a probabilistic reward-learning task sensitive to dopamine modulation. Levels of salivary caffeine and the primary caffeine metabolite paraxanthine were obtained on placebo and caffeine dosing days. Cardiovascular results revealed main effects of dose for diastolic blood pressure and heart rate; follow up tests showed that controls were most sensitive to 300 mg caffeine and 20 mg amphetamine; cocaine-dependent subjects were sensitive only to 300 mg caffeine. Subjective effects results revealed dose × time and dose × group interactions on the ARCI A, ARCI LSD, and VAS 'elated' scales; follow up tests did not show systematic differences between groups with regard to caffeine or d-amphetamine. Large between-group differences in salivary paraxanthine (but not salivary caffeine) levels were obtained under both caffeine doses. The cocaine-dependent group expressed significantly higher paraxanthine levels than controls under 150 mg and 3-4 fold greater levels under 300 mg at 90 min and 150 min post caffeine dose. However, these differences also covaried with cigarette smoking status (not balanced between groups), and nicotine smoking is known to alter caffeine/paraxanthine metabolism via cytochrome P450 enzymes. These preliminary data raise the possibility that adenosine antagonists may affect cocaine-dependent and non-dependent subjects differently. In conjunction with previous preclinical and

Auditory beat stimulation and its effects on cognition and mood States.

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Chaieb, Leila; Wilpert, Elke Caroline; Reber, Thomas P; Fell, Juergen

2015-01-01

Auditory beat stimulation may be a promising new tool for the manipulation of cognitive processes and the modulation of mood states. Here, we aim to review the literature examining the most current applications of auditory beat stimulation and its targets. We give a brief overview of research on auditory steady-state responses and its relationship to auditory beat stimulation (ABS). We have summarized relevant studies investigating the neurophysiological changes related to ABS and how they impact upon the design of appropriate stimulation protocols. Focusing on binaural-beat stimulation, we then discuss the role of monaural- and binaural-beat frequencies in cognition and mood states, in addition to their efficacy in targeting disease symptoms. We aim to highlight important points concerning stimulation parameters and try to address why there are often contradictory findings with regard to the outcomes of ABS.

Molecular imaging of drug-modulated protein-protein interactions in living subjects.

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Paulmurugan, Ramasamy; Massoud, Tarik F; Huang, Jing; Gambhir, Sanjiv S

2004-03-15

Networks of protein interactions mediate cellular responses to environmental stimuli and direct the execution of many different cellular functional pathways. Small molecules synthesized within cells or recruited from the external environment mediate many protein interactions. The study of small molecule-mediated interactions of proteins is important to understand abnormal signal transduction pathways in cancer and in drug development and validation. In this study, we used split synthetic renilla luciferase (hRLUC) protein fragment-assisted complementation to evaluate heterodimerization of the human proteins FRB and FKBP12 mediated by the small molecule rapamycin. The concentration of rapamycin required for efficient dimerization and that of its competitive binder ascomycin required for dimerization inhibition were studied in cell lines. The system was dually modulated in cell culture at the transcription level, by controlling nuclear factor kappaB promoter/enhancer elements using tumor necrosis factor alpha, and at the interaction level, by controlling the concentration of the dimerizer rapamycin. The rapamycin-mediated dimerization of FRB and FKBP12 also was studied in living mice by locating, quantifying, and timing the hRLUC complementation-based bioluminescence imaging signal using a cooled charged coupled device camera. This split reporter system can be used to efficiently screen small molecule drugs that modulate protein-protein interactions and also to assess drugs in living animals. Both are essential steps in the preclinical evaluation of candidate pharmaceutical agents targeting protein-protein interactions, including signaling pathways in cancer cells.

P3-10: Crossmodal Perceptual Grouping Modulates Subjective Causality between Action and Outcome

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Takahiro Kawabe

2012-10-01

Full Text Available Agents have to determine which external events their action has causally produced. A sensation of causal relation between action and outcome is called subjective causality. Subjective causality has been linked to the comparator model. This model assumes that the brain compares an internal prediction for action outcome with an actual sensory outcome, distinguishing between self and externally produced outcomes depending on spatiotemporal congruency. However, recent studies have expressed some doubt about the idea that subjective causality arises depending solely on the spatiotemporal congruency, suggesting instead that other perceptual/cognitive factors play a critical role in determining subjective causality. We hypothesized that crossmodal grouping between action and outcome contributed to subjective causality. Crossmodal temporal grouping is an essential factor for crossmodal simultaneity judgments with ungrouped crossmodal signals likely to be judged as non-simultaneous. We predicted that subjective causality would decrease when an agent's action was not temporally grouped with action outcome. In the experiment, observers were asked to press a key in order to trigger a display change with some temporal delay. To disrupt temporal grouping between action and outcome, a task-irrelevant visual flash or tone was sometimes presented synchronously with the button press and/or the display change. Subjective causality was decreased when the flash or the tone was coincided with the button press. This demonstrates that perceptual grouping has a key role in determination of subjective causality, a result that is not accounted for by the standard comparator model.

Nuclear Technology. Course 28: Welding Inspection. Module 28-6, Process Controls.

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Espy, John

This sixth in a series of ten modules for a course titled Welding Inspection describes procedures review, process monitoring, and weld defect analysis. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject matter, (6)…

Space Charge Modulated Electrical Breakdown of Oil Impregnated Paper Insulation Subjected to AC-DC Combined Voltages

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Yuanwei Zhu

2018-06-01

Full Text Available Based on the existing acknowledgment that space charge modulates AC and DC breakdown of insulating materials, this investigation promotes the related investigation into the situations of more complex electrical stress, i.e., AC-DC combined voltages. Experimentally, the AC-DC breakdown characteristics of oil impregnated paper insulation were systematically investigated. The effects of pre-applied voltage waveform, AC component ratio, and sample thickness on AC-DC breakdown characteristics were analyzed. After that, based on an improved bipolar charge transport model, the space charge profiles and the space charge induced electric field distortion during AC-DC breakdown were numerically simulated to explain the differences in breakdown characteristics between the pre-applied AC and pre-applied DC methods under AC-DC combined voltages. It is concluded that large amounts of homo-charges are accumulated during AC-DC breakdown, which results in significantly distorted inner electric field, leading to variations of breakdown characteristics of oil impregnated paper insulation. Therefore, space charges under AC-DC combined voltages must be considered in the design of converter transformers. In addition, this investigation could provide supporting breakdown data for insulation design of converter transformers and could promote better understanding on the breakdown mechanism of insulating materials subjected to AC-DC combined voltages.

On staggered indecomposable Virasoro modules

International Nuclear Information System (INIS)

Kytoelae, Kalle; Ridout, David

2009-01-01

In this article, certain indecomposable Virasoro modules are studied. Specifically, the Virasoro mode L 0 is assumed to be nondiagonalizable, possessing Jordan blocks of rank 2. Moreover, the module is further assumed to have a highest weight submodule, the 'left module', and that the quotient by this submodule yields another highest weight module, the 'right module'. Such modules, which have been called staggered, have appeared repeatedly in the logarithmic conformal field theory literature, but their theory has not been explored in full generality. Here, such a theory is developed for the Virasoro algebra using rather elementary techniques. The focus centers on two different but related questions typically encountered in practical studies: How can one identify a given staggered module, and how can one demonstrate the existence of a proposed staggered module. Given just the values of the highest weights of the left and right modules, themselves subject to simple necessary conditions, invariants are defined which together with the knowledge of the left and right modules uniquely identify a staggered module. The possible values of these invariants form a vector space of dimension 0, 1, or 2, and the structures of the left and right modules limit the isomorphism classes of the corresponding staggered modules to an affine subspace (possibly empty). The number of invariants and affine restrictions is purely determined by the structures of the left and right modules. Moreover, in order to facilitate applications, the expressions for the invariants and restrictions are given by formulas as explicit as possible (they generally rely on expressions for Virasoro singular vectors). Finally, the text is liberally peppered throughout with examples illustrating the general concepts. These have been carefully chosen for their physical relevance or for the novel features they exhibit.

On staggered indecomposable Virasoro modules

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Kytoelae, Kalle [Geneve Univ. (Switzerland); Ridout, David [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2009-06-15

In this article, certain indecomposable Virasoro modules are studied. Specifically, the Virasoro mode L0 is assumed to be non-diagonalisable, possessing Jordan blocks of rank two. Moreover, the module is further assumed to have a highest weight submodule, the ''left module'', and that the quotient by this submodule yields another highest weight module, the ''right module''. Such modules, which have been called staggered, have appeared repeatedly in the logarithmic conformal field theory literature, but their theory has not been explored in full generality. Here, such a theory is developed for the Virasoro algebra using rather elementary techniques. The focus centres on two different but related questions typically encountered in practical studies: How can one identify a given staggered module, and how can one demonstrate the existence of a proposed staggered module. Given just the values of the highest weights of the left and right modules, themselves subject to simple necessary conditions, invariants are defined which together with the knowledge of the left and right modules uniquely identify a staggered module. The possible values of these invariants form a vector space of dimension zero, one or two, and the structures of the left and right modules limit the isomorphism classes of the corresponding staggered modules to an affine subspace (possibly empty). The number of invariants and affine restrictions is purely determined by the structures of the left and right modules. Moreover, in order to facilitate applications, the expressions for the invariants and restrictions are given by formulae as explicit as possible (they generally rely on expressions for Virasoro singular vectors). Finally, the text is liberally peppered throughout with examples illustrating the general concepts. These have been carefully chosen for their physical relevance or for the novel features they exhibit. (orig.)

On staggered indecomposable Virasoro modules

International Nuclear Information System (INIS)

Kytoelae, Kalle; Ridout, David

2009-06-01

In this article, certain indecomposable Virasoro modules are studied. Specifically, the Virasoro mode L0 is assumed to be non-diagonalisable, possessing Jordan blocks of rank two. Moreover, the module is further assumed to have a highest weight submodule, the ''left module'', and that the quotient by this submodule yields another highest weight module, the ''right module''. Such modules, which have been called staggered, have appeared repeatedly in the logarithmic conformal field theory literature, but their theory has not been explored in full generality. Here, such a theory is developed for the Virasoro algebra using rather elementary techniques. The focus centres on two different but related questions typically encountered in practical studies: How can one identify a given staggered module, and how can one demonstrate the existence of a proposed staggered module. Given just the values of the highest weights of the left and right modules, themselves subject to simple necessary conditions, invariants are defined which together with the knowledge of the left and right modules uniquely identify a staggered module. The possible values of these invariants form a vector space of dimension zero, one or two, and the structures of the left and right modules limit the isomorphism classes of the corresponding staggered modules to an affine subspace (possibly empty). The number of invariants and affine restrictions is purely determined by the structures of the left and right modules. Moreover, in order to facilitate applications, the expressions for the invariants and restrictions are given by formulae as explicit as possible (they generally rely on expressions for Virasoro singular vectors). Finally, the text is liberally peppered throughout with examples illustrating the general concepts. These have been carefully chosen for their physical relevance or for the novel features they exhibit. (orig.)

On staggered indecomposable Virasoro modules

Science.gov (United States)

Kytölä, Kalle; Ridout, David

2009-12-01

In this article, certain indecomposable Virasoro modules are studied. Specifically, the Virasoro mode L0 is assumed to be nondiagonalizable, possessing Jordan blocks of rank 2. Moreover, the module is further assumed to have a highest weight submodule, the "left module," and that the quotient by this submodule yields another highest weight module, the "right module." Such modules, which have been called staggered, have appeared repeatedly in the logarithmic conformal field theory literature, but their theory has not been explored in full generality. Here, such a theory is developed for the Virasoro algebra using rather elementary techniques. The focus centers on two different but related questions typically encountered in practical studies: How can one identify a given staggered module, and how can one demonstrate the existence of a proposed staggered module. Given just the values of the highest weights of the left and right modules, themselves subject to simple necessary conditions, invariants are defined which together with the knowledge of the left and right modules uniquely identify a staggered module. The possible values of these invariants form a vector space of dimension 0, 1, or 2, and the structures of the left and right modules limit the isomorphism classes of the corresponding staggered modules to an affine subspace (possibly empty). The number of invariants and affine restrictions is purely determined by the structures of the left and right modules. Moreover, in order to facilitate applications, the expressions for the invariants and restrictions are given by formulas as explicit as possible (they generally rely on expressions for Virasoro singular vectors). Finally, the text is liberally peppered throughout with examples illustrating the general concepts. These have been carefully chosen for their physical relevance or for the novel features they exhibit.

Intensity modulation of cutaneous electrical stimulation: : EPs and subjective ratings

NARCIS (Netherlands)

van der Heide, E.M.; Buitenweg, Jan R.; Marani, Enrico; Rutten, Wim

2006-01-01

Chronic pain research is increasingly focused on the neuroplastic mechanisms underlying subjective pain experience. The latter is often measured using reported pain intensity, e.g. using a numeric rating scale (NRS). Evoked Potentials (EPs) reflect the cortical representation of applied stimuli and

Somatosensory Tinnitus: Correlation between Cranio-Cervico-Mandibular Disorder History and Somatic Modulation.

Science.gov (United States)

Ralli, Massimo; Altissimi, Giancarlo; Turchetta, Rosaria; Mazzei, Filippo; Salviati, Massimo; Cianfrone, Francesca; Orlando, Maria Patrizia; Testugini, Valeria; Cianfrone, Giancarlo

2016-01-01

In a subpopulation of patients, tinnitus can be modulated by movements of the jaw or head and neck due to complex somatosensory-auditory interactions. In some of these subjects, tinnitus could be related to an underlying temporomandibular (TMJ) or craniocervical (NECK) dysfunction that, if correctly identified, could streamline treatment and increase chances of tinnitus improvement. However, it is still unclear whether somatic modulation of tinnitus could be used as a screening tool for identifying such patients. In this study, we included 310 tinnitus patients with normal hearing, no psychiatric comorbidities, and a positive history of TMJ and/or NECK dysfunction and/or a positive modulation of tinnitus to evaluate the characteristics of somatic modulation, investigate the relationship between positive history and positive modulation, and identify factors most strongly associated with somatic modulation. Tinnitus modulation was present in 79.67% of the patients. We found a significant association within the same subjects between a positive history and a positive tinnitus modulation for the same region, mainly for TMJ in unilateral tinnitus patients and for TMJ + NECK in bilateral tinnitus patients. A strong correlation between history and modulation in the same somatic region within the same subgroups of subjects was also identified. Most TMJ maneuvers resulted in an increased loudness, while NECK maneuvers showed an increase in tinnitus loudness in about 59% of cases. High-pitched tinnitus and male gender were associated with a higher prevalence of modulation; no differences were found for tinnitus onset, Tinnitus Handicap Inventory score, and age. In this paper, we report a strong association between history and modulation for the same regions within the same patients; such an association should always be investigated to improve chances of a correct diagnosis of somatosensory tinnitus. © 2017 S. Karger AG, Basel.

Modulation of aesthetic value by semantic context: An fMRI study

DEFF Research Database (Denmark)

Kirk, Ulrich; Skov, Martin; Hulme, Oliver

2009-01-01

Aesthetic judgments, like most judgments, depend on context. Whether an object or image is seen in daily life or in an art gallery can significantly modulate the aesthetic value humans attach to it. We investigated the neural system supporting this modulation by presenting human subjects....... This contextual modulation correlated with activity in the medial orbitofrontal cortex and prefrontal cortex, whereas the context, independent of aesthetic value, correlated with bilateral activations of temporal pole and bilateral entorhinal cortex. This shows that prefrontal and orbitofrontal cortices recruited...... by aesthetic judgments are significantly biased by subjects' prior expectations about the likely hedonic value of stimuli according to their source....

Modulation detection as a function of carrier frequency and level

NARCIS (Netherlands)

Fassel, R.; Kohlrausch, A.G.

1995-01-01

This paper describes recent experiments investigating temporal processing in the auditory system. Subjects had to discriminate sinusoidal signals with a flat temporal envelope from those with a sinusoidal amplitude modulation. The modulation depth at threshold was measured for a wide range of

Determination of ETSPLs for the Sennheiser HDA 200 headphone and the Etymotic Research ER-2 insertphone and MAF in the frequency range 125 Hz to 16 kHz

DEFF Research Database (Denmark)

Han, Loc A.; Poulsen, Torben

1997-01-01

The binaural free field hearing threshold for pure tones (the minimum audible field, MAF) and Equivalent Threshold Sound Pressure Levels (ETSPL) for the Sennheiser HDA 200 earphone and the Etymotic Research ER-2 insert earphone have been determined for thirty-one otologically normal test subjects...

Bio-Inspired Innovation and National Security

Science.gov (United States)

2010-01-01

Doppler shift resulting from their own flight.35 They can also determine azimuth and elevation using binaural processing. Detection of wires is a...responses. The problem is that trained intelligence or military persons, psychopathic or antisocial subjects, and others can effectively beat the polygraph

Transient response of a polymer electrolyte membrane fuel cell subjected to time-varying modulating conditions

Energy Technology Data Exchange (ETDEWEB)

Noorani, S.; Shamim, T. [Michigan-Dearborn Univ., Dearborn, MI (United States). Dept. of Mechanical Engineering

2009-07-01

In order for fuel cells to compete with internal combustion engines, they must have significant advantages in terms of overall efficiency, weight, packaging, safety and cost. A key requirement is its ability to operate under highly transient conditions during start-up, acceleration, and deceleration with stable performance. Therefore, a better understanding of fuel cell dynamic behaviour is needed along with better water management and distributions inside the cell. Therefore, this study investigated the effect of transient conditions on water distribution inside a polymer electrolyte membrane (PEM) cell. A macroscopic single-fuel cell based, one-dimensional, isothermal mathematical model was used to study the effect of modulating cell voltage on the water distribution of anode, cathode, catalyst layers, and membrane. Compared to other existing models, this model did not rely on the non-physical assumption of the uptake curve equilibrium between the pore vapour and ionomer water in the catalyst layers. Instead, the transition between the two phases was modeled as a finite-rate equilibration process. The modulating conditions were simulated by forcing the temporal variations in fuel cell voltage. The results revealed that cell voltage modulations cause a departure in the cell behaviour from its steady behaviour, and the finite-rate equilibration between the catalyst vapour and liquid water can be a factor in determining the cell response. The cell response is also affected by the modulating frequency and amplitude. The peak cell response was observed at low frequencies. Keywords: fuel cell, water transport, dynamic behaviour, numerical simulations. 9 refs., 1 tab., 5 figs.

Strain-induced modulation of near-field radiative transfer.

Science.gov (United States)

Ghanekar, Alok; Ricci, Matthew; Tian, Yanpei; Gregory, Otto; Zheng, Yi

2018-06-11

In this theoretical study, we present a near-field thermal modulator that exhibits change in radiative heat transfer when subjected to mechanical stress/strain. The device has two terminals at different temperatures separated by vacuum: one fixed and one stretchable. The stretchable side contains one-dimensional grating. When subjected to mechanical strain, the effective optical properties of the stretchable side are affected upon deformation of the grating. This results in modulation of surface waves across the interfaces influencing near-field radiative heat transfer. We show that for a separation of 100 nm, it is possible to achieve 25% change in radiative heat transfer for a strain of 10%.

Assessing the Role of Place and Timing Cues in Coding Frequency and Amplitude Modulation as a Function of Age.

Science.gov (United States)

Whiteford, Kelly L; Kreft, Heather A; Oxenham, Andrew J

2017-08-01

Natural sounds can be characterized by their fluctuations in amplitude and frequency. Ageing may affect sensitivity to some forms of fluctuations more than others. The present study used individual differences across a wide age range (20-79 years) to test the hypothesis that slow-rate, low-carrier frequency modulation (FM) is coded by phase-locked auditory-nerve responses to temporal fine structure (TFS), whereas fast-rate FM is coded via rate-place (tonotopic) cues, based on amplitude modulation (AM) of the temporal envelope after cochlear filtering. Using a low (500 Hz) carrier frequency, diotic FM and AM detection thresholds were measured at slow (1 Hz) and fast (20 Hz) rates in 85 listeners. Frequency selectivity and TFS coding were assessed using forward masking patterns and interaural phase disparity tasks (slow dichotic FM), respectively. Comparable interaural level disparity tasks (slow and fast dichotic AM and fast dichotic FM) were measured to control for effects of binaural processing not specifically related to TFS coding. Thresholds in FM and AM tasks were correlated, even across tasks thought to use separate peripheral codes. Age was correlated with slow and fast FM thresholds in both diotic and dichotic conditions. The relationship between age and AM thresholds was generally not significant. Once accounting for AM sensitivity, only diotic slow-rate FM thresholds remained significantly correlated with age. Overall, results indicate stronger effects of age on FM than AM. However, because of similar effects for both slow and fast FM when not accounting for AM sensitivity, the effects cannot be unambiguously ascribed to TFS coding.

A subject-independent pattern-based Brain-Computer Interface

Directory of Open Access Journals (Sweden)

Andreas Markus Ray

2015-10-01

Full Text Available While earlier Brain-Computer Interface (BCI studies have mostly focused on modulating specific brain regions or signals, new developments in pattern classification of brain states are enabling real-time decoding and modulation of an entire functional network. The present study proposes a new method for real-time pattern classification and neurofeedback of brain states from electroencephalographic (EEG signals. It involves the creation of a fused classification model based on the method of Common Spatial Patterns (CSPs from data of several healthy individuals. The subject-independent model is then used to classify EEG data in real-time and provide feedback to new individuals. In a series of offline experiments involving training and testing of the classifier with individual data from 27 healthy subjects, a mean classification accuracy of 75.30% was achieved, demonstrating that the classification system at hand can reliably decode two types of imagery used in our experiments, i.e. happy emotional imagery and motor imagery. In a subsequent experiment it is shown that the classifier can be used to provide neurofeedback to new subjects, and that these subjects learn to match their brain pattern to that of the fused classification model in a few days of neurofeedback training. This finding can have important implications for future studies on neurofeedback and its clinical applications on neuropsychiatric disorders.

Feedback of mechanical effectiveness induces adaptations in motor modules during cycling

Science.gov (United States)

De Marchis, Cristiano; Schmid, Maurizio; Bibbo, Daniele; Castronovo, Anna Margherita; D'Alessio, Tommaso; Conforto, Silvia

2013-01-01

Recent studies have reported evidence that the motor system may rely on a modular organization, even if this behavior has yet to be confirmed during motor adaptation. The aim of the present study is to investigate the modular motor control mechanisms underlying the execution of pedaling by untrained subjects in different biomechanical conditions. We use the muscle synergies framework to characterize the muscle coordination of 11 subjects pedaling under two different conditions. The first one consists of a pedaling exercise with a strategy freely chosen by the subjects (Preferred Pedaling Technique, PPT), while the second condition constrains the gesture by means of a real time visual feedback of mechanical effectiveness (Effective Pedaling Technique, EPT). Pedal forces, recorded using a pair of instrumented pedals, were used to calculate the Index of Effectiveness (IE). EMG signals were recorded from eight muscles of the dominant leg and Non-negative Matrix Factorization (NMF) was applied for the extraction of muscle synergies. All the synergy vectors, extracted cycle by cycle for each subject, were pooled across subjects and conditions and underwent a 2-dimensional Sammon's non-linear mapping. Seven representative clusters were identified on the Sammon's projection, and the corresponding eight-dimensional synergy vectors were used to reconstruct the repertoire of muscle activation for all subjects and all pedaling conditions (VAF > 0.8 for each individual muscle pattern). Only 5 out of the 7 identified modules were used by the subjects during the PPT pedaling condition, while 2 additional modules were found specific for the pedaling condition EPT. The temporal recruitment of three identified modules was highly correlated with IE. The structure of the identified modules was found similar to that extracted in other studies of human walking, partly confirming the existence of shared and task specific muscle synergies, and providing further evidence on the modularity

Auditory beat stimulation and its effects on cognition and mood states

Directory of Open Access Journals (Sweden)

Leila eChaieb

2015-05-01

Full Text Available Auditory beat stimulation may be a promising new tool for the manipulation of cognitive processes and the modulation of mood-states. Here we aim to review the literature examining the most current applications of auditory beat stimulation and its targets. We give a brief overview of research on auditory steady-state responses and its relationship to auditory beat stimulation. We have summarized relevant studies investigating the neurophysiological changes related to auditory beat stimulation and how they impact upon the design of appropriate stimulation protocols. Focusing on binaural beat stimulation, we then discuss the role of monaural and binaural beat frequencies in cognition and mood-states, in addition to their efficacy in targeting disease symptoms. We aim to highlight important points concerning stimulation parameters and try to address why there are often contradictory findings with regard to the outcomes of auditory beat stimulation.

Subjective emotional experience at different stages of Parkinson's disease.

Science.gov (United States)

Vicente, Siobhan; Péron, Julie; Biseul, Isabelle; Ory, Sophie; Philippot, Pierre; Drapier, Sophie; Drapier, Dominique; Vérin, Marc

2011-11-15

Subjective emotional experience is thought to rely on a large cortical-subcortical network including orbitofrontal and cingulate frontostriatal circuits together with the mesolimbic dopaminergic system that modulates their activity. Parkinson's disease (PD) provides a model for exploring this issue. By using an original emotion induction procedure, the present study examined to what extent subjective experience of emotion of PD patients at different stages of the disease was modulated by emotion in the same way as healthy individuals. A battery of film excerpts was used to elicit different emotional feelings (happiness, anger, fear, sadness, disgust, and neutral) in 15 newly diagnosed PD patients, 18 patients with advanced PD and 15 matched controls. The newly diagnosed patients were examined in two conditions: "on" and "off" dopaminergic medication. Participants reported the intensity of their emotional feelings on a scale consisting of 10 emotional categories. Results indicated that PD patients at different stages of the disease did not significantly differ from the controls in the self-reported emotional experience to the presented film excerpts. Moreover, analyses conducted within the newly diagnosed PD group (on-dopa vs. off-dopa conditions) indicated that the patients' emotional reactivity to the presented film excerpts was not significantly modulated by dopaminergic medication. These results thus question the possible role of dopaminergic pathways in subjective emotional experience, at least in this sample and in the context of emotion induction. Copyright © 2011 Elsevier B.V. All rights reserved.

Modulation of Immune Functions by Foods

Directory of Open Access Journals (Sweden)

Shuichi Kaminogawa

2004-01-01

Full Text Available Evidence is rapidly accumulating as to the beneficial effects of foods. However, it is not always clear whether the information is based on data evaluated impartially in a scientific fashion. Human research into whether foods modulate immune functions in either intervention studies or randomized controlled trials can be classified into three categories according to the physical state of subjects enrolled for investigation: (i studies examining the effect of foods in healthy individuals; (ii studies analyzing the effect of foods on patients with hypersensitivity; and (iii studies checking the effect of foods on immunocompromized subjects, including patients who had undergone surgical resection of cancer and newborns. The systematization of reported studies has made it reasonable to conclude that foods are able to modulate immune functions manifesting as either innate immunity (phagocytic activity, NK cell activity or acquired immunity (T cell response, antibody production. Moreover, improvement of immune functions by foods can normalize the physical state of allergic patients or cancer patients, and may reduce the risk of diseases in healthy individuals. Therefore, it is valuable to assess the immune-modulating abilities of foods by measuring at least one parameter of either innate or acquired immunity.

Optimizing Energy and Modulation Selection in Multi-Resolution Modulation For Wireless Video Broadcast/Multicast

KAUST Repository

She, James

2009-11-01

Emerging technologies in Broadband Wireless Access (BWA) networks and video coding have enabled high-quality wireless video broadcast/multicast services in metropolitan areas. Joint source-channel coded wireless transmission, especially using hierarchical/superposition coded modulation at the channel, is recognized as an effective and scalable approach to increase the system scalability while tackling the multi-user channel diversity problem. The power allocation and modulation selection problem, however, is subject to a high computational complexity due to the nonlinear formulation and huge solution space. This paper introduces a dynamic programming framework with conditioned parsing, which significantly reduces the search space. The optimized result is further verified with experiments using real video content. The proposed approach effectively serves as a generalized and practical optimization framework that can gauge and optimize a scalable wireless video broadcast/multicast based on multi-resolution modulation in any BWA network.

Optimizing Energy and Modulation Selection in Multi-Resolution Modulation For Wireless Video Broadcast/Multicast

KAUST Repository

She, James; Ho, Pin-Han; Shihada, Basem

2009-01-01

Emerging technologies in Broadband Wireless Access (BWA) networks and video coding have enabled high-quality wireless video broadcast/multicast services in metropolitan areas. Joint source-channel coded wireless transmission, especially using hierarchical/superposition coded modulation at the channel, is recognized as an effective and scalable approach to increase the system scalability while tackling the multi-user channel diversity problem. The power allocation and modulation selection problem, however, is subject to a high computational complexity due to the nonlinear formulation and huge solution space. This paper introduces a dynamic programming framework with conditioned parsing, which significantly reduces the search space. The optimized result is further verified with experiments using real video content. The proposed approach effectively serves as a generalized and practical optimization framework that can gauge and optimize a scalable wireless video broadcast/multicast based on multi-resolution modulation in any BWA network.

Ageing monitoring in IGBT module under sinusoidal loading

DEFF Research Database (Denmark)

Ghimire, Pramod; Pedersen, Kristian Bonderup; Rannestad, Bjørn

2015-01-01

This paper presents monitoring of ageing in high power insulated gate bipolar transistor (IGBT) modules subjected to sinusoidal loading at nominal power level. On-state voltage for IGBT, diode, and rise in interconnection resistance are used as ageing parameters. These are measured in three...... different ways: calibration of power modules after 24 h of operation, offline characterization every 5 min of operation, and continuous measurement during normal converter operation. Four power modules are tested, which are cycled to different degradation levels by number of cycles, where one is tested...

Auditory psychophysics: spectrotemporal representation of signals

NARCIS (Netherlands)

de Boer, E.; Dreschler, W. A.

1987-01-01

The study of audition has widened: Having been concentrated in the 1960s on a few topics like pitch perception, binaural hearing, and fatigue, it now spans many more subjects. In the present paper we have emphasized the following topics: frequency analysis--this topic includes spectral integration

Genetic Schizophrenia Risk Variants Jointly Modulate Total Brain and White Matter Volume

DEFF Research Database (Denmark)

Terwisscha van Scheltinga, Afke F; Bakker, Steven C; van Haren, Neeltje E M

2013-01-01

with total brain volume (R(2)=.048, p=1.6×10(-4)) and white matter volume (R(2)=.051, p=8.6×10(-5)) equally in patients and control subjects. The number of (independent) SNPs that substantially influenced both disease risk and white matter (n=2020) was much smaller than the entire set of SNPs that modulated...... modulating schizophrenia and brain volume. METHODS: Odds ratios for genome-wide SNP data were calculated in the sample collected by the Psychiatric Genome-wide Association Study Consortium (8690 schizophrenia patients and 11,831 control subjects, excluding subjects from the present study). These were used...

Hypertension module: an interactive learning tool in physiology.

Science.gov (United States)

Işman, C A; Gülpinar, M A; Kurtel, H; Alican, I; Yeğen, B C

2003-12-01

The aim of the present study was to evaluate the strong or weak aspects of an interactive study module introduced during the "Cardiovascular and Respiratory Systems Subject Committee" in the second year of the medical program. Five study groups consisting of 25 students attended two-hour module sessions for six weeks with the same tutor. According to the module assessment questionnaire, the majority of the students assessed the module as excellent or good. The students reported that they had gained not only in knowledge but also in skills development. The general opinion of the students was that both the organization and the implementation of the module met their expectations. Nearly one-half of the students reported that their expectations with regard to the educational environment and the participation of students were fully met. The major weakness in this new educational trial appears to be assessment of the module.

A Matlab/Simulink-Based Interactive Module for Servo Systems Learning

Science.gov (United States)

Aliane, N.

2010-01-01

This paper presents an interactive module for learning both the fundamental and practical issues of servo systems. This module, developed using Simulink in conjunction with the Matlab graphical user interface (Matlab-GUI) tool, is used to supplement conventional lectures in control engineering and robotics subjects. First, the paper introduces the…

A spatial approach of magnitude-squared coherence applied to selective attention detection.

Science.gov (United States)

Bonato Felix, Leonardo; de Souza Ranaudo, Fernando; D'affonseca Netto, Aluizio; Ferreira Leite Miranda de Sá, Antonio Mauricio

2014-05-30

Auditory selective attention is the human ability of actively focusing in a certain sound stimulus while avoiding all other ones. This ability can be used, for example, in behavioral studies and brain-machine interface. In this work we developed an objective method - called Spatial Coherence - to detect the side where a subject is focusing attention to. This method takes into consideration the Magnitude Squared Coherence and the topographic distribution of responses among electroencephalogram electrodes. The individuals were stimulated with amplitude-modulated tones binaurally and were oriented to focus attention to only one of the stimuli. The results indicate a contralateral modulation of ASSR in the attention condition and are in agreement with prior studies. Furthermore, the best combination of electrodes led to a hit rate of 82% for 5.03 commands per minute. Using a similar paradigm, in a recent work, a maximum hit rate of 84.33% was achieved, but with a greater a classification time (20s, i.e. 3 commands per minute). It seems that Spatial Coherence is a useful technique for detecting focus of auditory selective attention. Copyright © 2014 Elsevier B.V. All rights reserved.

Evoked response of heart rate variability using short-duration white noise.

Science.gov (United States)

Lee, Guo-She; Chen, Mei-Ling; Wang, Gin-You

2010-06-24

To investigate and to establish a model for evaluation of the instant cardiovascular responses to the noises of low-to-moderate intensity, sixteen healthy subjects were enrolled. The white noises were binaurally presented with a supra-aural earphone. The test intensities of noises were no noise, 50, 60, 70 and 80 dBA. Each noise was continued for 5 min and the electrocardiogram was simultaneously recorded. The cardiac autonomic responses were evaluated using power spectral analysis of the R-R contour obtained from digital signal processing of the ECG tracings. The result showed that the mean heart rate and mean blood pressure did not change significantly with the noises. However, the low-frequency power (LF) which represents cardiac autonomic modulations and the ratio (LHR) of LF to high-frequency power (HF) which reflects cardiac sympathetic modulations were significantly greater in the noise intensity of 50, 60, 70 and 80dBA (pnoise intensity (rho=0.90, pwhite noises can be detected using power spectral analysis of heart rate variability and the evoked responses may provide a sensitive way to evaluate the instant effect of noise to humans.

Use Case Analysis: The Ambulatory EEG in Navy Medicine for Traumatic Brain Injuries

Science.gov (United States)

2016-12-01

science of binaural beats . Retrieved from http://binauralbrains.com/the-science-of- binaural - beats / Biosignal. (2016). MicroEEG. Retrieved from http...Cap. Source: Binaural Brains (n.d.). ....................................4  Figure 3.  EEG Machine. Source: Refine Medical Technology (n.d...EEG. Figures 2, 3, and 4 display images of a standard EEG cap, EEG machine, and an EEG recording. Figure 2. Standard EEG Cap. Source: Binaural Brains

Medical students as human subjects in educational research

Directory of Open Access Journals (Sweden)

Adina L. Kalet

2013-02-01

Full Text Available Introduction: Special concerns often arise when medical students are themselves the subjects of education research. A recently completed large, multi-center randomized controlled trial of computer-assisted learning modules for surgical clerks provided the opportunity to explore the perceived level of risk of studies where medical students serve as human subjects by reporting on: 1 the response of Institutional Review Boards (IRBs at seven institutions to the same study protocol; and 2 the thoughts and feelings of students across study sites about being research subjects. Methods: From July 2009 to August 2010, all third-year medical students at seven collaborating institutions were eligible to participate. Patterns of IRB review of the same protocol were compared. Participation burden was calculated in terms of the time spent interacting with the modules. Focus groups were conducted with medical students at each site. Transcripts were coded by three independent reviewers and analyzed using Atlas.ti. Results: The IRBs at the seven participating institutions granted full (n=1, expedited (n=4, or exempt (n=2 review of the WISE Trial protocol. 995 (73% of those eligible consented to participate, and 207 (20% of these students completed all outcome measures. The average time to complete the computer modules and associated measures was 175 min. Common themes in focus groups with participant students included the desire to contribute to medical education research, the absence of coercion to consent, and the low-risk nature of the research. Discussion: Our findings demonstrate that risk assessment and the extent of review utilized for medical education research vary among IRBs. Despite variability in the perception of risk implied by differing IRB requirements, students themselves felt education research was low risk and did not consider themselves to be vulnerable. The vast majority of eligible medical students were willing to participate as research

Effects of diazepam and levodopa single doses on motor cortex plasticity modulation in healthy human subjects: A TMS study

Directory of Open Access Journals (Sweden)

Ilić Nela V.

2012-01-01

Full Text Available Introduction. Administration of pharmacological agents with specific actions on neurotransmitter systems is a powerful driver of functional cortical reorganization. Plastic reorganization of the motor cortex in humans studies by the use of non-invasive stimulation protocols, which mimic the Hebbian model of associative plasticity. Objective. Aiming to explore pharmacological modulation on human motor cortex plasticity, we tested healthy subjects after each dosage of diazepam, levodopa i placebo administration, using paired associative stimulation protocol (PAS that induce fenomena similar to a long-term potentiation and depression, as defined on the synaptic level. Methods. We analyzed effects of benzodiazepines (10 mg, levodopa (200 mg and placebo on PAS protocol in 14 healthy volunteers, using a double-blind placebo-controlled study design. PAS consisted of electrical stimuli pairs at n.medianus and magnetic pulses over the scalp (transcranial magnetic stimulation in precisely defined intervals (ISI was 10 and 25 ms for a total of about 15 minutes (200 pairs. MEP amplitudes before and after (0, 10, 20 and 30 minutes later interventional protocols were compared. Results. When protocols were applied with placebo depending on ISI (10 ms - inhibitory, 25 ms - facilitatory effects, MEP amplitudes decreased or increased, while values in the postinterventional period (0, 10, 20 and 30 min were compared with initial values before the use of SAS. The use of benzodiazepines caused the occlusion of LTP-like effect, in contrast to amplification effects recorded after the administration of levodopa. With respect to the LTD-like protocol, the reverse was true (ANOVA for repeat measurements p<0.001. Conclusion. Administration of GABA-ergic agonist diazepam interferes with the induction of associative plasticity in the motor cortex of healthy individuals, as opposed to the use of levodopa, which stimulates these processes. The observed effects point at a

Interaural time sensitivity of high-frequency neurons in the inferior colliculus.

Science.gov (United States)

Yin, T C; Kuwada, S; Sujaku, Y

1984-11-01

Recent psychoacoustic experiments have shown that interaural time differences provide adequate cues for lateralizing high-frequency sounds, provided the stimuli are complex and not pure tones. We present here physiological evidence in support of these findings. Neurons of high best frequency in the cat inferior colliculus respond to interaural phase differences of amplitude modulated waveforms, and this response depends upon preservation of phase information of the modulating signal. Interaural phase differences were introduced in two ways: by interaural delays of the entire waveform and by binaural beats in which there was an interaural frequency difference in the modulating waveform. Results obtained with these two methods are similar. Our results show that high-frequency cells can respond to interaural time differences of amplitude modulated signals and that they do so by a sensitivity to interaural phase differences of the modulating waveform.

Design and development of neutral beam module components

International Nuclear Information System (INIS)

Holl, P.M.; Bulmer, R.H.; Dilgard, L.W.; Horvath, J.A.; Molvik, A.W.; Porter, G.D.; Shearer, J.W.; Slack, D.S.; Colonias, J.S.

1979-01-01

The Mirror Fusion Test Facility (MFTF) injection system consists of twenty 20 keV start-up, and twenty-four 80 keV sustaining neutral beam source modules. The neutral beam modules are mounted in four clusters equally spaced around the waist of the vacuum vessel which contains the superconducting magnets. A module is defined here as an assembly consisting of a beam source and the interfacing components between that beam source and the vacuum chamber. Six major interfacing components are the subject of this paper. They are the magnetic shield, the neutralizer duct, the isolation valve, mounting gimbals, aiming bellows and actuators

Allosteric Modulation of Muscarinic Acetylcholine Receptors

Czech Academy of Sciences Publication Activity Database

Jakubík, Jan; El-Fakahany, E. E.

2010-01-01

Roč. 3, č. 9 (2010), s. 2838-2860 ISSN 1424-8247 R&D Projects: GA ČR GA305/09/0681 Institutional research plan: CEZ:AV0Z50110509 Keywords : muscarinic acetylcholine receptors * allosteric modulation * Alzheimer´s disease Subject RIV: CE - Biochemistry

Chinese-English Electronics and Telecommunications Dictionary. Volume 2

Science.gov (United States)

1976-11-01

atrutted pole 18 «»W strutted pole 19 XI ’oubllng 20 KS<(itf« double conversion reception 21 XS^fl double beat 22 MMBLm double reaction 23...double-break Jack; double 13 interruption Jack binaural localization IU bitelephone; biphone 15 binaural hearing 16 binaural effect 17... binaural 18 bltelephone receiver 19 duodlode-trlode 20 duodlode-trlode; double 21 dlode-trlode; duplex dlode-trlode double diode-tetrode 22 double

Discontinuous modulation functions and their application for analysis of modulated structures with the computing system JANA2006

Czech Academy of Sciences Publication Activity Database

Petříček, Václav; Eigner, Václav; Dušek, Michal; Čejchan, Antonín

2016-01-01

Roč. 231, č. 5 (2016), s. 301-312 ISSN 2194-4946 R&D Projects: GA MŠk LO1603 Institutional support: RVO:68378271 Keywords : crystal structure analysis * Jana2006 * modulated structures Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.179, year: 2016

Pengembangan Modul Bimbingan dan Konseling untuk Pencegahan Bullying di Sekolah

Directory of Open Access Journals (Sweden)

Hengki Yandri

2013-03-01

Full Text Available This research aims to formulate guidance and counseling module to prevent bullying at school and to describe the level of applicability used by counselor. The method used was ADDIE model development. The subjects of the research consisted of guidance and counseling expert and the intended target of the module (counselor, chosen through purposive sampling. The instruments used were questionnaire and focus group discussion (FGD. The data were analyzed descriptively. The results showed that prototype modules developed to prevent bullying at school is applicable used by the counselor and those modules can be utilized by counselor to prevent bullying at school.

Effects of amplitude modulation on perception of wind turbine noise

Energy Technology Data Exchange (ETDEWEB)

Yoon, Ki Seop; Lee, Soo Gab; Gwak, Doo Young [Dept. of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Seong, Yeol Wan [Ammunition Engineering Team, Defense Agency for Technology and Quality, Daejeon (Korea, Republic of); Lee, Seung Hoon [Aerodynamics Research Team, Korea Aerospace Research Institute, Daejeon (Korea, Republic of); Hong, Ji Young [Transportation Environmental Research Team, Green Transport and Logistics Institute, Korea Railroad Research Institute, Uiwang (Korea, Republic of)

2016-10-15

Wind turbine noise is considered to be easily detectable and highly annoying at relatively lower sound levels than other noise sources. Many previous studies attributed this characteristic to amplitude modulation. However, it is unclear whether amplitude modulation is the main cause of these properties of wind turbine noise. Therefore, the aim of the current study is to identify the relationship between amplitude modulation and these two properties of wind turbine noise. For this investigation, two experiments were conducted. In the first experiment, 12 participants determined the detection thresholds of six target sounds in the presence of background noise. In the second experiment, 12 participants matched the loudness of modified sounds without amplitude modulation to that of target sounds with amplitude modulation. The results showed that the detection threshold was lowered as the modulation depth increased; additionally, sounds with amplitude modulation had higher subjective loudness than those without amplitude modulation.

Effects of amplitude modulation on perception of wind turbine noise

International Nuclear Information System (INIS)

Yoon, Ki Seop; Lee, Soo Gab; Gwak, Doo Young; Seong, Yeol Wan; Lee, Seung Hoon; Hong, Ji Young

2016-01-01

Wind turbine noise is considered to be easily detectable and highly annoying at relatively lower sound levels than other noise sources. Many previous studies attributed this characteristic to amplitude modulation. However, it is unclear whether amplitude modulation is the main cause of these properties of wind turbine noise. Therefore, the aim of the current study is to identify the relationship between amplitude modulation and these two properties of wind turbine noise. For this investigation, two experiments were conducted. In the first experiment, 12 participants determined the detection thresholds of six target sounds in the presence of background noise. In the second experiment, 12 participants matched the loudness of modified sounds without amplitude modulation to that of target sounds with amplitude modulation. The results showed that the detection threshold was lowered as the modulation depth increased; additionally, sounds with amplitude modulation had higher subjective loudness than those without amplitude modulation

Serotonin modulates immune function in T cells from HIV-seropositive subjects

DEFF Research Database (Denmark)

Eugen-Olsen, J; Afzelius, P; Andresen, L

1997-01-01

We have shown earlier increased intracellular levels of cAMP in peripheral lymphocytes from HIV-seropositive subjects and that a chemically induced decrease in this level increases cell proliferation and cytotoxicity. Others have shown that serotonin indirectly decreases intracellular cAMP levels...

Physiological modulation of eustachian tube function.

Science.gov (United States)

Leclerc, J E; Doyle, W J; Karnavas, W

1987-01-01

The effect of changing body position on the Eustachian tube opening time (TOT) and nasal conductance (NC) was investigated in 5 subjects. Eustachian tube function was evaluated using a sonotubometric technique and NC was determined by anterior or posterior rhinomanometry. The results showed that both the TOT and NC were decreased by changing the body position from erect to recumbent. On a different day, Eustachian tube function and rhinomanometry tests were repeated every 30 min over a 5-7 h period. The results documented a nasal cycle in all subjects. Moreover, TOT tracked the ipsilateral NC in 3 subjects and the contralateral NC in 2 subjects. Since TOT measures mucosal venous congestion, these findings suggest that the tubal mucosa also experiences autonomically modulated cyclic fluctuations.

Getting Down to Business: Travel Agency, Module 9. [Student Guide]. Entrepreneurship Training Components.

Science.gov (United States)

Rassen, Rachel L.

This module on owning and operating a travel agency is one of 36 modules in a series on entrepreneurship. The introduction tells the student what topics will be covered and suggests other modules to read in related occupations. Each unit includes student goals, a case study, and a discussion of the unit subject matter. Learning activities are…

Task-induced frequency modulation features for brain-computer interfacing

Science.gov (United States)

Jayaram, Vinay; Hohmann, Matthias; Just, Jennifer; Schölkopf, Bernhard; Grosse-Wentrup, Moritz

2017-10-01

Objective. Task-induced amplitude modulation of neural oscillations is routinely used in brain-computer interfaces (BCIs) for decoding subjects’ intents, and underlies some of the most robust and common methods in the field, such as common spatial patterns and Riemannian geometry. While there has been some interest in phase-related features for classification, both techniques usually presuppose that the frequencies of neural oscillations remain stable across various tasks. We investigate here whether features based on task-induced modulation of the frequency of neural oscillations enable decoding of subjects’ intents with an accuracy comparable to task-induced amplitude modulation. Approach. We compare cross-validated classification accuracies using the amplitude and frequency modulated features, as well as a joint feature space, across subjects in various paradigms and pre-processing conditions. We show results with a motor imagery task, a cognitive task, and also preliminary results in patients with amyotrophic lateral sclerosis (ALS), as well as using common spatial patterns and Laplacian filtering. Main results. The frequency features alone do not significantly out-perform traditional amplitude modulation features, and in some cases perform significantly worse. However, across both tasks and pre-processing in healthy subjects the joint space significantly out-performs either the frequency or amplitude features alone. This result only does not hold for ALS patients, for whom the dataset is of insufficient size to draw any statistically significant conclusions. Significance. Task-induced frequency modulation is robust and straight forward to compute, and increases performance when added to standard amplitude modulation features across paradigms. This allows more information to be extracted from the EEG signal cheaply and can be used throughout the field of BCIs.

The ATLAS semiconductor tracker end-cap module

Czech Academy of Sciences Publication Activity Database

Abdesselam, A.; Adkin, P. J.; Allport, P.; Böhm, Jan; Šťastný, Jan

2007-01-01

Roč. 575, - (2007), s. 353-389 ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10100502 Keywords : ATLAS * SCT * silicon * microstrip * module * LHC Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.114, year: 2007

On the precision of neural computation with interaural level differences in the lateral superior olive

Czech Academy of Sciences Publication Activity Database

Bureš, Zbyněk; Maršálek, P.

2013-01-01

Roč. 1536, Nov 6 (2013), s. 16-26 ISSN 0006-8993 R&D Projects: GA ČR(CZ) GAP303/12/1347 Grant - others:GA MZd(CZ) NT11532 Institutional support: RVO:68378041 Keywords : binaural hearing * interaural level difference * just -noticeable difference Subject RIV: FH - Neurology Impact factor: 2.828, year: 2013

Circadian profile of cardiac autonomic nervous modulation in healthy subjects

DEFF Research Database (Denmark)

Bonnemeier, Hendrik; Richardt, Gert; Potratz, Jürgen

2003-01-01

UNLABELLED: Circadian Profile of Heart Rate Variability. INTRODUCTION: Although heart rate variability (HRV) has been established as a tool to study cardiac autonomic activity, almost no data are available on the circadian patterns of HRV in healthy subjects aged 20 to 70 years. METHODS AND RESULTS...... higher in men. Younger men also exhibited significantly higher values...... parasympathetic activity. The significant gender-related difference of HRV decreases with aging. These findings emphasize the need to determine age-, gender-, and nycthemeral-dependent normal ranges for HRV assessment....

Efficacy of Theta Binaural Beats for the Treatment of Chronic Pain.

Science.gov (United States)

Zampi, Donna D

2016-01-01

According to the National Institutes of Health, in 2011, chronic pain affected from approximately 10% to >50% of the adult population in the United States, with a cost of $61 billion to US businesses annually. The pilot study assessed the effects that an external, audio, neural stimulus of theta binaural beats (TBB) had on returning the brain neurosignature for chronic pain to homeostasis. The quantitative, experimental, repeated-measures crossover study compared the results of 2 interventions in 2 time-order sequences. An a priori analysis indicated a sample size of 28 participants was needed for a 2-way repeated-measures analysis of variance (ANOVA). The study was conducted in Richmond, VA, USA, with participants recruited from the financial sector. Thirty-six US adults with various types of chronic pain, and with a median age of 47 y, ranging in ages from 26-69 y, participated in the study. The study experienced 4 dropouts. Participants listened to 2 recordings-one using TBB at 6 Hz (TBB intervention) and one using a placebo of a nonbinaural beat tone of 300 Hz (sham intervention) for 20 min daily. Both interventions lasted 14 successive days each, with some participants hearing the TBB intervention first and the sham intervention second and some hearing them in the reverse order. Participants listened to the interventions via a Web site on the Internet or via a compact disc. Interviews were conducted either in person or telephonically with e-mail support. Using the West Haven-Yale Multidimensional Pain Inventory (MPI), potential changes in perceived severity of chronic pain were measured (1) at baseline; (2) after the first test at 14 d, either TBB or sham intervention; and (3) after the second test at 28 d-either TBB or sham intervention. The analysis compared the average mean for pretest and first and second posttest scores. The analysis indicated a large main effect for the TBB intervention in reducing perceived pain severity, P<.001 (F2,60=84.98, r=0

Modelling PV modules' performance in Sahelian climates

Energy Technology Data Exchange (ETDEWEB)

Diarra, D.C.; Akuffo, F.O. [Kwame Nkrumah Univ. of Science and Technology, Kumasi (Ghana). Dept. of Mechanical Engineering

2003-08-01

This paper describes the development of a thermo-optical model designed to evaluate the temperature of a photovoltaic (PV) module in an effort to design a cost-effective cooling system for PV modules operating under high ambient temperatures. The power output of a PV module is greatly reduced when its temperature rises. This loss in efficiency is particularly significant in Sahelian regions where PV modules are subjected to high solar radiation intensities and high ambient temperatures. The newly developed thermo-optical model confirms that most of the heat in a PV module is generated in the solar cell. The results of the analysis include: the optical absorption, reflection and transmission of the solar radiation incident on the module; the temperature distribution in the module; and, the heat transfer through the top and bottom of the module. At incidence angles of 60 degrees, approximately three-quarters of the heat is generated in the solar cell. The optical efficiency is 88.44 per cent at normal incidence angle and 82.48 per cent when the incidence angle is 60 degrees. It was determined that the cooling system should be located as close as possible to the solar cell in order to increase the thermal heat flow from the cell. 4 refs., 3 tabs., 4 figs.

Asymmetric Hearing Loss in Chinese Workers Exposed to Complex Noise.

Science.gov (United States)

Wang, Xiaoxiao; Li, Nan; Zeng, Lin; Tao, Liyuan; Zhang, Hua; Yang, Qiuling; Qiu, Wei; Zhu, Liangliang; Zhao, Yiming

2016-01-01

Evaluate the audiometric asymmetry in Chinese industrial workers and investigate the effects of noise exposure, sex, and binaural average thresholds on audiometric asymmetry. Data collected from Chinese industrial workers during a cross-sectional study were reanalyzed. Of the 1388 workers, 266 met the inclusion criteria for this study. Each subject underwent a physical examination and an otologic examination and completed a health-related questionnaire. χ and t tests were used to examine the differences between the asymmetric and symmetric hearing loss groups. One hundred thirty-one subjects (49.2%) had a binaural hearing threshold difference of 15 dB or more for at least one frequency, and there was no statistically significant difference between the left and right ears. The asymmetric hearing loss group was not exposed to higher cumulative noise levels (t = 0.522, p = 0.602), and there was no dose-response relation between asymmetry and cumulative noise levels (χ = 6.502, p = 0.165). Men were 1.849 times more likely to have asymmetry than women were (95% confidence interval, 1.051 to 3.253). Among the workers with higher high-frequency hearing thresholds, audiometric asymmetry was 1.024 times more prevalent than that among those with lower high-frequency hearing thresholds (95% confidence interval, 1.004 to 1.044). The results indicated that occupational noise exposure contributed minimally to asymmetry, whereas sex and binaural average thresholds significantly affected audiometric asymmetry. There was no evidence that the left ears were worse than the right ears.

Modulating presence and impulsiveness by external stimulation of the brain

Directory of Open Access Journals (Sweden)

Baumgartner Thomas

2008-08-01

Full Text Available Abstract Background "The feeling of being there" is one possible way to describe the phenomenon of feeling present in a virtual environment and to act as if this environment is real. One brain area, which is hypothesized to be critically involved in modulating this feeling (also called presence is the dorso-lateral prefrontal cortex (dlPFC, an area also associated with the control of impulsive behavior. Methods In our experiment we applied transcranial direct current stimulation (tDCS to the right dlPFC in order to modulate the experience of presence while watching a virtual roller coaster ride. During the ride we also registered electro-dermal activity. Subjects also performed a test measuring impulsiveness and answered a questionnaire about their presence feeling while they were exposed to the virtual roller coaster scenario. Results Application of cathodal tDCS to the right dlPFC while subjects were exposed to a virtual roller coaster scenario modulates the electrodermal response to the virtual reality stimulus. In addition, measures reflecting impulsiveness were also modulated by application of cathodal tDCS to the right dlPFC. Conclusion Modulating the activation with the right dlPFC results in substantial changes in responses of the vegetative nervous system and changed impulsiveness. The effects can be explained by theories discussing the top-down influence of the right dlPFC on the "impulsive system".

High repetition rate driver circuit for modulation of injection lasers

International Nuclear Information System (INIS)

Dornan, B.R.; Goel, J.; Wolkstein, H.J.

1981-01-01

An injection laser modulator comprises a self-biased field effect transistor (FET) and an injection laser to provide a quiescent state during which lasing of the injection laser occurs in response to a high repetition rate signal of pulse coded modulation (pcm). The modulator is d.c. coupled to an input pulse source of pcm rendering it compatible with an input pulse referenced to ground and not being subject to voltage level shifting of the input pulse. The modulator circuit in its preferred and alternate embodiments provides various arrangements for high impedance input and low impedance output matching. In addition, means are provided for adjusting the bias of the FET as well as the bias of the injection laser

Reaching consensus: a review on sexual health training modules for professional capacity building

Directory of Open Access Journals (Sweden)

Zahra Karimian

2018-01-01

Full Text Available Background: Professional capacity building (PCB is the focus point in health-related subjects.The present study was conducted to systematically review the existing sexual health training modules for health care providers.Methods: The following keywords were used to search: training, education, professional capacity, practitioner, sexual health, skill education, module, course, package and curriculum.The term MESH is referred to Medical Subject Headings and the following databases were investigated: MEDLINE, EMBASE, PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL, The Cochrane Library and Web of Science, Scopus, Google Scholar, SID,Magiran, and Iranmedex. All articles from 1980 to 2015 were extracted. Online modules were excluded. Considering that lesson plan was the basis of instruction, the modules were selected based on the characteristics of the lesson plans.Results: A total number of 38 published training modules in the field of sexuality we redetermined. In total, more than half of the modules (58% were designed for medical doctor sand allied health professionals and the remaining (42% were for nurses and midwives. Almost all the modules (97% were introduced and utilized in developed countries, and only 3% were disseminated in developing countries.Conclusion: There are invaluable modules to build professional capacity in the field of sexual health. As a number of modules have been designed for nurses and midwifes, as the first-line health care providers, the use of these groups in sexual counseling and empowerment for sexual health is essential. No sexual health training program was designed in Iran. Therefore, designing such modules according to Iranian culture is strongly recommended.

Reaching consensus: a review on sexual health training modules for professional capacity building.

Science.gov (United States)

Karimian, Zahra; Azin, Seied Ali; Javid, Nasrin; Araban, Marzieh; Maasoumi, Raziyeh; Aghayan, Shahrokh; Merghati Khoie, Effat

2018-01-01

Background: Professional capacity building (PCB) is the focus point in health-related subjects.The present study was conducted to systematically review the existing sexual health training modules for health care providers. Methods: The following keywords were used to search: training, education, professional capacity, practitioner, sexual health, skill education, module, course, package and curriculum.The term MESH is referred to Medical Subject Headings and the following databases were investigated: MEDLINE, EMBASE, PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), The Cochrane Library and Web of Science, Scopus, Google Scholar, SID,Magiran, and Iranmedex. All articles from 1980 to 2015 were extracted. Online modules were excluded. Considering that lesson plan was the basis of instruction, the modules were selected based on the characteristics of the lesson plans. Results: A total number of 38 published training modules in the field of sexuality we redetermined. In total, more than half of the modules (58%) were designed for medical doctor sand allied health professionals and the remaining (42%) were for nurses and midwives. Almost all the modules (97%) were introduced and utilized in developed countries, and only 3% were disseminated in developing countries. Conclusion: There are invaluable modules to build professional capacity in the field of sexual health. As a number of modules have been designed for nurses and midwifes, as the first-line health care providers, the use of these groups in sexual counseling and empowerment for sexual health is essential. No sexual health training program was designed in Iran. Therefore, designing such modules according to Iranian culture is strongly recommended.

Module theory, extending modules and generalizations

CERN Document Server

Tercan, Adnan

2016-01-01

The main focus of this monograph is to offer a comprehensive presentation of known and new results on various generalizations of CS-modules and CS-rings. Extending (or CS) modules are generalizations of injective (and also semisimple or uniform) modules. While the theory of CS-modules is well documented in monographs and textbooks, results on generalized forms of the CS property as well as dual notions are far less present in the literature. With their work the authors provide a solid background to module theory, accessible to anyone familiar with basic abstract algebra. The focus of the book is on direct sums of CS-modules and classes of modules related to CS-modules, such as relative (injective) ejective modules, (quasi) continuous modules, and lifting modules. In particular, matrix CS-rings are studied and clear proofs of fundamental decomposition results on CS-modules over commutative domains are given, thus complementing existing monographs in this area. Open problems round out the work and establish the...

Auditory cortical neurons are sensitive to static and continuously changing interaural phase cues.

Science.gov (United States)

Reale, R A; Brugge, J F

1990-10-01

1. The interaural-phase-difference (IPD) sensitivity of single neurons in the primary auditory (AI) cortex of the anesthetized cat was studied at stimulus frequencies ranging from 120 to 2,500 Hz. Best frequencies of the 43 AI cells sensitive to IPD ranged from 190 to 2,400 Hz. 2. A static IPD was produced when a pair of low-frequency tone bursts, differing from one another only in starting phase, were presented dichotically. The resulting IPD-sensitivity curves, which plot the number of discharges evoked by the binaural signal as a function of IPD, were deeply modulated circular functions. IPD functions were analyzed for their mean vector length (r) and mean interaural phase (phi). Phase sensitivity was relatively independent of best frequency (BF) but highly dependent on stimulus frequency. Regardless of BF or stimulus frequency within the excitatory response area the majority of cells fired maximally when the ipsilateral tone lagged the contralateral signal and fired least when this interaural-phase relationship was reversed. 3. Sensitivity to continuously changing IPD was studied by delivering to the two ears 3-s tones that differed slightly in frequency, resulting in a binaural beat. Approximately 26% of the cells that showed a sensitivity to static changes in IPD also showed a sensitivity to dynamically changing IPD created by this binaural tonal combination. The discharges were highly periodic and tightly synchronized to a particular phase of the binaural beat cycle. High synchrony can be attributed to the fact that cortical neurons typically respond to an excitatory stimulus with but a single spike that is often precisely timed to stimulus onset. A period histogram, binned on the binaural beat frequency (fb), produced an equivalent IPD-sensitivity function for dynamically changing interaural phase. For neurons sensitive to both static and continuously changing interaural phase there was good correspondence between their static (phi s) and dynamic (phi d

Three different up-titration regimens of ponesimod, an S1P1 receptor modulator, in healthy subjects.

Science.gov (United States)

Scherz, Michael W; Brossard, Patrick; D'Ambrosio, Daniele; Ipek, Murat; Dingemanse, Jasper

2015-06-01

Ponesimod is a selective S1P1 receptor modulator, and induces dose-dependent reduction of circulating lymphocytes upon oral dosing. Previous studies showed that single doses up to 75 mg or multiple doses up to 40 mg once daily are well tolerated, and heart rate (HR) reduction and atrio-ventricular conduction delays upon treatment initiation are reduced by gradual up-titration to the maintenance dose. This single-center, open-label, randomized, multiple-dose, 3-treatment, 3-way crossover study compared the tolerability, safety, pharmacokinetics, cardiodynamics, and effects on lymphocytes of 3 different up-titration regimens of ponesimod in healthy male and female subjects. Up-titration regimens comprised escalating periods of b.i.d. dosing (2.5 or 5 mg) and q.d. dosing (10 or 20 mg or both). After the third up-titration period a variable-duration washout period of 1-3 days was followed by re-challenge with a single 20-mg dose of ponesimod. Adverse events were transient and mild to moderate in intensity, not different between regimens. HR decrease after the first dose was greater than after all subsequent doses, including up-titration doses. Little or no HR change was observed with morning doses of b.i.d. regimens, suggesting that 2.5 and 5 mg b.i.d. are sufficient to sustain cardiac desensitization for the 12-hours dosing interval. © 2015, The American College of Clinical Pharmacology.

The barrel modules of the ATLAS semiconductor tracker

Czech Academy of Sciences Publication Activity Database

Abdesselam, A.; Akimoto, T.; Allport, P.; Böhm, Jan; Šťastný, Jan

2006-01-01

Roč. 568, - (2006), s. 642-671 ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10100502 Keywords : ATLAS * SCT * silicon * microstrip * module * LHC * barrel Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.185, year: 2006

Stuttering adults' lack of pre-speech auditory modulation normalizes when speaking with delayed auditory feedback.

Science.gov (United States)

Daliri, Ayoub; Max, Ludo

2018-02-01

Auditory modulation during speech movement planning is limited in adults who stutter (AWS), but the functional relevance of the phenomenon itself remains unknown. We investigated for AWS and adults who do not stutter (AWNS) (a) a potential relationship between pre-speech auditory modulation and auditory feedback contributions to speech motor learning and (b) the effect on pre-speech auditory modulation of real-time versus delayed auditory feedback. Experiment I used a sensorimotor adaptation paradigm to estimate auditory-motor speech learning. Using acoustic speech recordings, we quantified subjects' formant frequency adjustments across trials when continually exposed to formant-shifted auditory feedback. In Experiment II, we used electroencephalography to determine the same subjects' extent of pre-speech auditory modulation (reductions in auditory evoked potential N1 amplitude) when probe tones were delivered prior to speaking versus not speaking. To manipulate subjects' ability to monitor real-time feedback, we included speaking conditions with non-altered auditory feedback (NAF) and delayed auditory feedback (DAF). Experiment I showed that auditory-motor learning was limited for AWS versus AWNS, and the extent of learning was negatively correlated with stuttering frequency. Experiment II yielded several key findings: (a) our prior finding of limited pre-speech auditory modulation in AWS was replicated; (b) DAF caused a decrease in auditory modulation for most AWNS but an increase for most AWS; and (c) for AWS, the amount of auditory modulation when speaking with DAF was positively correlated with stuttering frequency. Lastly, AWNS showed no correlation between pre-speech auditory modulation (Experiment II) and extent of auditory-motor learning (Experiment I) whereas AWS showed a negative correlation between these measures. Thus, findings suggest that AWS show deficits in both pre-speech auditory modulation and auditory-motor learning; however, limited pre

Microscopic prediction of speech intelligibility in spatially distributed speech-shaped noise for normal-hearing listeners.

Science.gov (United States)

Geravanchizadeh, Masoud; Fallah, Ali

2015-12-01

A binaural and psychoacoustically motivated intelligibility model, based on a well-known monaural microscopic model is proposed. This model simulates a phoneme recognition task in the presence of spatially distributed speech-shaped noise in anechoic scenarios. In the proposed model, binaural advantage effects are considered by generating a feature vector for a dynamic-time-warping speech recognizer. This vector consists of three subvectors incorporating two monaural subvectors to model the better-ear hearing, and a binaural subvector to simulate the binaural unmasking effect. The binaural unit of the model is based on equalization-cancellation theory. This model operates blindly, which means separate recordings of speech and noise are not required for the predictions. Speech intelligibility tests were conducted with 12 normal hearing listeners by collecting speech reception thresholds (SRTs) in the presence of single and multiple sources of speech-shaped noise. The comparison of the model predictions with the measured binaural SRTs, and with the predictions of a macroscopic binaural model called extended equalization-cancellation, shows that this approach predicts the intelligibility in anechoic scenarios with good precision. The square of the correlation coefficient (r(2)) and the mean-absolute error between the model predictions and the measurements are 0.98 and 0.62 dB, respectively.

Neural Mechanisms of the Transformation from Objective Value to Subjective Utility: Converting from Count to Worth

Science.gov (United States)

Kurnianingsih, Yoanna A.; Mullette-Gillman, O'Dhaniel A.

2016-01-01

When deciding, we aim to choose the “best” possible outcome. This is not just selection of the option that is the most numerous or physically largest, as options are translated from objective value (count) to subjective value (worth or utility). We localized the neural instantiation of the value-to-utility transformation to the dorsal anterior midcingulate cortex (daMCC), with independent replication. The daMCC encodes the context-specific information necessary to convert from count to worth. This encoding is not simply a representation of utility or preference, but the interaction of the two. Specifically, the relationship of brain activation to value is dependent on individual preference, with both positive and negative slopes across the population depending on whether each individual's preference results in enhancement or diminishment of the valuation. For a given value, across participants, enhanced daMCC activation corresponds to diminished subjective valuation, deactivation to enhanced subjective valuation, and non-modulated activation with non-modulated subjective valuation. Further, functional connectivity analyses identified brain regions (positive connectivity with the inferior frontal gyrus and negative connectivity with the nucleus accumbens) through which contextual information may be integrated into the daMCC and allow for outputs to modulate valuation signals. All analyses were replicated through an independent within-study replication, with initial testing in the gains domain and replication in the intermixed and mirrored losses trials. We also present and discuss an ancillary finding: we were unable to identify parametric value signals for losses through whole-brain analyses, and ROI analyses of the vmPFC presented non-modulation across loss value levels. These results identify the neural locus of the value-to-utility transformation, and provide a specific computational function for the daMCC in the production of subjective valuation through

Practice changes beta power at rest and its modulation during movement in healthy subjects but not in patients with Parkinson's disease.

Science.gov (United States)

Moisello, Clara; Blanco, Daniella; Lin, Jing; Panday, Priya; Kelly, Simon P; Quartarone, Angelo; Di Rocco, Alessandro; Cirelli, Chiara; Tononi, Giulio; Ghilardi, M Felice

2015-10-01

PD (Parkinson's disease) is characterized by impairments in cortical plasticity, in beta frequency at rest and in beta power modulation during movement (i.e., event-related ERS [synchronization] and ERD [desynchronization]). Recent results with experimental protocols inducing long-term potentiation in healthy subjects suggest that cortical plasticity phenomena might be reflected by changes of beta power recorded with EEG during rest. Here, we determined whether motor practice produces changes in beta power at rest and during movements in both healthy subjects and patients with PD. We hypothesized that such changes would be reduced in PD. We thus recorded EEG in patients with PD and age-matched controls before, during and after a 40-minute reaching task. We determined posttask changes of beta power at rest and assessed the progressive changes of beta ERD and ERS during the task over frontal and sensorimotor regions. We found that beta ERS and ERD changed significantly with practice in controls but not in PD. In PD compared to controls, beta power at rest was greater over frontal sensors but posttask changes, like those during movements, were far less evident. In both groups, kinematic characteristics improved with practice; however, there was no correlation between such improvements and the changes in beta power. We conclude that prolonged practice in a motor task produces use-dependent modifications that are reflected in changes of beta power at rest and during movement. In PD, such changes are significantly reduced; such a reduction might represent, at least partially, impairment of cortical plasticity.

Motor modules in robot-aided walking

Directory of Open Access Journals (Sweden)

Gizzi Leonardo

2012-10-01

Full Text Available Abstract Background It is hypothesized that locomotion is achieved by means of rhythm generating networks (central pattern generators and muscle activation generating networks. This modular organization can be partly identified from the analysis of the muscular activity by means of factorization algorithms. The activity of rhythm generating networks is described by activation signals whilst the muscle intervention generating network is represented by motor modules (muscle synergies. In this study, we extend the analysis of modular organization of walking to the case of robot-aided locomotion, at varying speed and body weight support level. Methods Non Negative Matrix Factorization was applied on surface electromyographic signals of 8 lower limb muscles of healthy subjects walking in gait robotic trainer at different walking velocities (1 to 3km/h and levels of body weight support (0 to 30%. Results The muscular activity of volunteers could be described by low dimensionality (4 modules, as for overground walking. Moreover, the activation signals during robot-aided walking were bursts of activation timed at specific phases of the gait cycle, underlying an impulsive controller, as also observed in overground walking. This modular organization was consistent across the investigated speeds, body weight support level, and subjects. Conclusions These results indicate that walking in a Lokomat robotic trainer is achieved by similar motor modules and activation signals as overground walking and thus supports the use of robotic training for re-establishing natural walking patterns.

Modulation of collective cell behaviour by geometrical constraints

Czech Academy of Sciences Publication Activity Database

Lunova, M.; Zablotskyy, Vitaliy A.; Dempsey, N.M.; Devillers, T.; Jirsa, M.; Syková, E.; Kubinová, Šárka; Lunov, Oleg; Dejneka, Alexandr

2016-01-01

Roč. 8, č. 11 (2016), s. 1099-1110 ISSN 1757-9694 Grant - others:AV ČR(CZ) Fellowship J. E. Purkyně Institutional support: RVO:68378271 Keywords : modulation * collective cell * geometrical constraints Subject RIV: BO - Biophysics Impact factor: 3.252, year: 2016

Neural coding and perception of pitch in the normal and impaired human auditory system

DEFF Research Database (Denmark)

Santurette, Sébastien

2011-01-01

that the use of spectral cues remained plausible. Simulations of auditory-nerve representations of the complex tones further suggested that a spectrotemporal mechanism combining precise timing information across auditory channels might best account for the behavioral data. Overall, this work provides insights...... investigated using psychophysical methods. First, hearing loss was found to affect the perception of binaural pitch, a pitch sensation created by the binaural interaction of noise stimuli. Specifically, listeners without binaural pitch sensation showed signs of retrocochlear disorders. Despite adverse effects...... of reduced frequency selectivity on binaural pitch perception, the ability to accurately process the temporal fine structure (TFS) of sounds at the output of the cochlear filters was found to be essential for perceiving binaural pitch. Monaural TFS processing also played a major and independent role...

Is there a risk to safety when working in the New South Wales underground coal-mining industry while having binaural noise-induced hearing loss?

Energy Technology Data Exchange (ETDEWEB)

Viljoen, D.A.; Nie, V.; Guest, M. [University of Newcastle, Newcastle, NSW (Australia)

2006-03-15

This study is designed to investigate the possible association between hearing loss and accidents in the New South Wales underground coal-mining industry. The study was conducted, gathering data over a 10-year period from 1994 to 2003, which identified 97 cases that have had accidents and 983 controls that have had no accidents. Hearing loss levels were noted and compared in the cases and controls. Multiple logistic regression was used to determine whether the variables were significant risk factors in the occurrence of accidents. Hearing loss levels in the total cohort varied from 0 to 54%. The proportion of cases with hearing loss appeared to be significantly higher in the young age group of {lt} 29 years than in the controls, but was not significantly different in the older age groups. This study indicates that workers who have lost up to 54% binaural high tone hearing and are older than 29 years do not appear to have an increased risk to safety when compared with workers who do not have hearing loss. However, workers in the young age group of {lt} 29 years who have high tone hearing loss may be at an increased risk of accident.

Audibility of modulation noise in stationary signals

NARCIS (Netherlands)

Neelen, J.J.M.

1970-01-01

Recordings of an acoustic signal on magnetic tape often show noise, which may be divided into two main classes: additive noise and multiplicative noise. A characteristic of the latter is that it is weak with weak signals and strong with strong signals. This modulation noise has been subjected to a

Passive listening to preferred motor tempo modulates corticospinal excitability.

Science.gov (United States)

Michaelis, Kelly; Wiener, Martin; Thompson, James C

2014-01-01

Rhythms are an essential characteristic of our lives, and auditory-motor coupling affects a variety of behaviors. Previous research has shown that the neural regions associated with motor system processing are coupled to perceptual rhythmic and melodic processing such that the perception of rhythmic stimuli can entrain motor system responses. However, the degree to which individual preference modulates the motor system is unknown. Recent work has shown that passively listening to metrically strong rhythms increases corticospinal excitability, as indicated by transcranial magnetic stimulation (TMS). Furthermore, this effect is modulated by high-groove music, or music that inspires movement, while neuroimaging evidence suggests that premotor activity increases with tempos occurring within a preferred tempo (PT) category. PT refers to the rate of a hypothetical endogenous oscillator that may be indicated by spontaneous motor tempo (SMT) and preferred perceptual tempo (PPT) measurements. The present study investigated whether listening to a rhythm at an individual's PT preferentially modulates motor system excitability. SMT was obtained in human participants through a tapping task in which subjects were asked to tap a response key at their most comfortable rate. Subjects listened a 10-beat tone sequence at 11 log-spaced tempos and rated their preference for each (PPT). We found that SMT and PPT measurements were correlated, indicating that preferred and produced tempos occurred at a similar rate. Crucially, single-pulse TMS delivered to left M1 during PPT judgments revealed that corticospinal excitability, measured by motor-evoked potentials (MEPs), was modulated by tempos traveling closer to individual PT. However, the specific nature of this modulation differed across individuals, with some exhibiting an increase in excitability around PT and others exhibiting a decrease. These findings suggest that auditory-motor coupling induced by rhythms is preferentially

New insight on bismuth cuprates with incommensurate modulated structures

Czech Academy of Sciences Publication Activity Database

Mironov, A. V.; Petříček, Václav; Khasanova, N. R.; Antipov, E. V.

2016-01-01

Roč. 72, č. 3 (2016), s. 395-403 ISSN 2052-5206 Institutional support: RVO:68378271 Keywords : modulated structure * high Tc superconductor * superspace approach Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.032, year: 2016

Irreducible Specht modules are signed Young modules

OpenAIRE

Hemmer, David J.

2005-01-01

Recently Donkin defined signed Young modules as a simultaneous generalization of Young and twisted Young modules for the symmetric group. We show that in odd characteristic, if a Specht module $S^\\lambda$ is irreducible, then $S^\\lambda$ is a signed Young module. Thus the set of irreducible Specht modules coincides with the set of irreducible signed Young modules. This provides evidence for our conjecture that the signed Young modules are precisely the class of indecomposable self-dual module...

Interactions of DNA repair gene variants modulate chromosomal aberrations in healthy subjects

Czech Academy of Sciences Publication Activity Database

Vodička, Pavel; Musak, L.; Frank, Ch.; Kazimirová, A.; Vymetálková, Veronika; Barančoková, M.; Smolková, B.; Dzupinková, Z.; Jirásková, Kateřina; Vodenková, Soňa; Kroupa, Michal; Osina, O.; Naccarati, Alessio; Palitti, F.; Forsti,, A.; Dusinska, M.; Vodičková, Ludmila; Hemminki, K.

2015-01-01

Roč. 36, č. 11 (2015), s. 1299-1306 ISSN 0143-3334 R&D Projects: GA ČR(CZ) GA15-14789S Institutional support: RVO:68378041 Keywords : individual susceptibility * colorectal - cancer * oxidative damage Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.874, year: 2015

Standard Practice for Visual Inspections of Photovoltaic Modules

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 This practice covers procedures and criteria for visual inspections of photovoltaic modules. 1.2 Visual inspections of photovoltaic modules are normally performed before and after modules have been subjected to environmental, electrical, or mechanical stress testing, such as thermal cycling, humidity-freeze cycling, damp heat exposure, ultraviolet exposure, mechanical loading, hail impact testing, outdoor exposure, or other stress testing that may be part of photovoltaic module testing sequence. 1.3 This practice does not establish pass or fail levels. The determination of acceptable or unacceptable results is beyond the scope of this practice. 1.4 There is no similar or equivalent ISO standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Environmental testing of terrestrial flat plate photovoltaic modules

Science.gov (United States)

Hoffman, A.; Griffith, J.

1979-01-01

The Low-Cost Solar Array (LSA) Project at the Jet Propulsion Laboratory has as one objective: the development and implementation of environmental tests for flat plate photovoltaic modules as part of the Department of Energy's terrestrial photovoltaic program. Modules procured under this program have been subjected to a variety of laboratory tests intended to simulate service environments, and the results of these tests have been compared to available data from actual field service. This comparison indicates that certain tests (notably temperature cycling, humidity cycling, and cyclic pressure loading) are effective indicators of some forms of field failures. Other tests have yielded results useful in formulating module design guidelines. Not all effects noted in field service have been successfully reproduced in the laboratory, however, and work is continuing in order to improve the value of the test program as a tool for evaluating module design and workmanship. This paper contains a review of these ongoing efforts and an assessment of significant test results to date.

Localization by interaural time difference (ITD): Effects of interaural frequency mismatch

International Nuclear Information System (INIS)

Bonham, B.H.; Lewis, E.R.

1999-01-01

A commonly accepted physiological model for lateralization of low-frequency sounds by interaural time delay (ITD) stipulates that binaural comparison neurons receive input from frequency-matched channels from each ear. Here, the effects of hypothetical interaural frequency mismatches on this model are reported. For this study, the cat close-quote s auditory system peripheral to the binaural comparison neurons was represented by a neurophysiologically derived model, and binaural comparison neurons were represented by cross-correlators. The results of the study indicate that, for binaural comparison neurons receiving input from one cochlear channel from each ear, interaural CF mismatches may serve to either augment or diminish the effective difference in ipsilateral and contralateral axonal time delays from the periphery to the binaural comparison neuron. The magnitude of this increase or decrease in the effective time delay difference can be up to 400 μs for CF mismatches of 0.2 octaves or less for binaural neurons with CFs between 250 Hz and 2.5 kHz. For binaural comparison neurons with nominal CFs near 500 Hz, the 25-μs effective time delay difference caused by a 0.012-octave CF mismatch is equal to the ITD previously shown to be behaviorally sufficient for the cat to lateralize a low-frequency sound source. copyright 1999 Acoustical Society of America.

Test system for thermoelectric modules and materials

Czech Academy of Sciences Publication Activity Database

Hejtmánek, Jiří; Knížek, Karel; Švejda, V.; Horna, P.; Sikora, M.

2014-01-01

Roč. 43, č. 10 (2014), s. 3726-3732 ISSN 0361-5235 R&D Projects: GA ČR GA13-17538S Institutional support: RVO:68378271 Keywords : thermoelectric power module * automatic thermoelectric testing setup * heat flow measurement * power generation * heat recovery Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.798, year: 2014

Learning from Online Modules in Diverse Instructional Contexts

Directory of Open Access Journals (Sweden)

Gwen Nugent

2016-06-01

Full Text Available Learning objects originally developed for use in online learning environments can also be used to enhance face-to-face instruction. This study examined the learning impacts of online learning objects packaged into modules and used in different contexts for undergraduate education offered on campus at three institutions. A multi-case study approach was used, examining learning impacts across a variety of course subjects, course levels (introductory and advanced undergraduate, student levels (undergraduate and graduate, and instructional goals (i.e., replacement for lecture, remediation. A repeated measures design was used, with learning data collected prior to viewing the online module, after completion of the module, and at the end of the semester. The study provided a broad examination of ways that online modules are typically used in a college classroom, as well as measured learning effectiveness based on different instructional purpose and usage contexts. Results showed the effectiveness of the modules in serving as a substitute for classroom lecture, remediation of course prerequisite material, introduction to content with follow-up lab practice, and review for final exams. In each of these cases, the use of the modules resulted in significant learning increases, as well as retention of the learning until the end of the semester.

Signed Young Modules and Simple Specht Modules

OpenAIRE

Danz, Susanne; Lim, Kay Jin

2015-01-01

By a result of Hemmer, every simple Specht module of a finite symmetric group over a field of odd characteristic is a signed Young module. While Specht modules are parametrized by partitions, indecomposable signed Young modules are parametrized by certain pairs of partitions. The main result of this article establishes the signed Young module labels of simple Specht modules. Along the way we prove a number of results concerning indecomposable signed Young modules that are of independent inter...

Influence of Architectural Features and Styles on Various Acoustical Measures in Churches

Science.gov (United States)

Carvalho, Antonio Pedro Oliveira De.

16% in the differences between the predicted and real RTs. Using binaural measurements and subjective information collected in these churches, BACH (Binaural Acoustical CoHerence), a new binaural measure, is presented. A linear correlation coefficient near 0.7 was found between BACH and the subjective quality ratings, supporting the hypothesis that it can be useful in predicting the quality of music in churches. In conclusion, this study revealed important acoustical and architectural parameters and their relations, providing the basic information to predict several acoustical measures in churches at early stages of design or without the need of measurements in the real buildings.

Chemical reactions in the presence of surface modulation and stirring

OpenAIRE

Kamhawi, Khalid; Náraigh, Lennon Ó

2009-01-01

We study the dynamics of simple reactions where the chemical species are confined on a general, time-modulated surface, and subjected to externally-imposed stirring. The study of these inhomogeneous effects requires a model based on a reaction-advection-diffusion equation, which we derive. We use homogenization methods to show that up to second order in a small scaling parameter, the modulation effects on the concentration field are asymptotically equivalent for systems with or without stirri...

Developing Project Based Learning E-Module for the Course of Video Editing

Directory of Open Access Journals (Sweden)

Ketut Krisnayuni

2017-04-01

Full Text Available This study examined the development of an electronic module for the course of video editing and analyzed the students’ response of the e-module. A waterfall model was adopted in the development process of the e-module that consisted of five stages namely (1 analysis; (2 design; (3 implementation; (4 evaluation; and (5 maintenance. The subjects of this study were the students of class XI at SMK Negeri 1 Sukasada. Project Based Learning was used as the basis of the e-module development as the most relevant learning model to meet the students’needs and the schools’ situation. The data of the students’ response about the e-module were collected through a questionnaire. The students’ response was very positive indicated by the mean score of 94,37. It was concluded that the developed e-modul was categorized as very good.

Stimulus train duration but not attention moderates γ-band entrainment abnormalities in schizophrenia

Science.gov (United States)

Hamm, Jordan P.; Bobilev, Anastasia M.; Hayrynen, Lauren K.; Hudgens-Haney, Matthew E.; Oliver, William T.; Parker, David A.; McDowell, Jennifer E.; Buckley, Peter A.; Clementz, Brett A.

2017-01-01

Electroencephalographic (EEG) studies of auditory steady-state responses (aSSRs) non-invasively probe gamma-band (40-Hz) oscillatory capacity in sensory cortex with high signal-to-noise ratio. Consistent reports of reduced 40-Hz aSSRs in persons with schizophrenia (SZ) indicate its potential as an efficient biomarker for the disease, but studies have been limited to passive or indirect listening contexts with stereotypically short (500ms) stimulus trains. An inability to modulate sensorineural processing in accord with behavioral goals or within the sensory environmental context may represent a fundamental deficit in SZ, but whether and how this deficit relates to reduced aSSRs is unknown. We systematically varied stimulus duration and attentional contexts to further mature the 40-Hz aSSR as biomarker for future translational or mechanistic studies. Eighteen SZ and 18 healthy subjects (H) were presented binaural pure-tones with or without sinusoidal amplitude modulation at 40-Hz. Stimulus duration (500-ms or 1500-ms) and attention (via a button press task) were varied across 4 separate blocks. Evoked potentials recorded with dense-array EEGs were analyzed in the time-frequency domain. SZ displayed reduced 40-Hz aSSRs to typical stimulation parameters, replicating previous findings. In H, aSSRs were reduced when stimuli were presented in longer trains and were slightly enhanced by attention. Only the former modulation was impaired in SZ and correlated with sensory discrimination performance. Thus, gamma-band aSSRs are modulated by both attentional and stimulus duration contexts, but only modulations related to physical stimulus properties are abnormal in SZ, supporting its status as a biomarker of psychotic perceptual disturbance involving non-attentional sensori-cortical circuits. PMID:25868936

CMS Pixel Upgrade for the Phase I: Module Production and Qualification

CERN Document Server

AUTHOR|(CDS)2078028

2016-01-01

The present CMS pixel detector has been designed to be fully efficient up to a LHC luminosity of $10^{34}~\\mathrm{cm}^{-2}~\\mathrm{s}^{-1}$. However, the luminosity will increase by a factor of two in the coming years. Therefore it is planned to build and install a new detector in the extended year-end technical stop (YETS) in 2016-17. Barrel pixel modules are in production since Spring/Summer 2015 in five different centers. Module production requires bump bonding, wire bonding and gluing processes to finally assemble a full module. To have a uniform performance of all modules standard qualification procedures have been developed. All modules will be subjected to 10 termal cycles between +$17^{\\circ}$C and -$25^{\\circ }$C and then electrically tested. In addition, module performance will be verified under high rate X-rays, and internal calibrate signals used for electrical tests will be calibrated in units of electrons using well defined X-ray fluorescence lines from different target materials. The qualifica...

Amplitude modulation reduces loudness adaptation to high-frequency tones.

Science.gov (United States)

Wynne, Dwight P; George, Sahara E; Zeng, Fan-Gang

2015-07-01

Long-term loudness perception of a sound has been presumed to depend on the spatial distribution of activated auditory nerve fibers as well as their temporal firing pattern. The relative contributions of those two factors were investigated by measuring loudness adaptation to sinusoidally amplitude-modulated 12-kHz tones. The tones had a total duration of 180 s and were either unmodulated or 100%-modulated at one of three frequencies (4, 20, or 100 Hz), and additionally varied in modulation depth from 0% to 100% at the 4-Hz frequency only. Every 30 s, normal-hearing subjects estimated the loudness of one of the stimuli played at 15 dB above threshold in random order. Without any amplitude modulation, the loudness of the unmodulated tone after 180 s was only 20% of the loudness at the onset of the stimulus. Amplitude modulation systematically reduced the amount of loudness adaptation, with the 100%-modulated stimuli, regardless of modulation frequency, maintaining on average 55%-80% of the loudness at onset after 180 s. Because the present low-frequency amplitude modulation produced minimal changes in long-term spectral cues affecting the spatial distribution of excitation produced by a 12-kHz pure tone, the present result indicates that neural synchronization is critical to maintaining loudness perception over time.

Status Report on Speech Research, July-December 1981.

Science.gov (United States)

1981-01-01

there is a difference in the intercept of the beat straight-line fit for /i-u/ and /u- u/ cases; that is, rounding for the second vowel begins earlier... BINAURAL ] PRESENTATION I I tI I I I I I I I •I II II I ,V III I P" J II I base isolated transitions (to one ear) (to other. ear) DUPLEX-PRODUCING...frequency modulation, particularly as they relate to classical auditory phenomena such as beats and periodicity pitch. In general, however, research on

Studi Komparasi Modul Kimia Berbasis Media Screen Reader Jaws dan Braille Terhadap Prestasi, Motivasi, dan Kemandirian Belajar Peserta Didik Difabel Netra

Directory of Open Access Journals (Sweden)

Jamil Suprihatiningrum

2014-12-01

Full Text Available This study aimed to compare the achievement, motivation, and independent learning of blind students who use screen reader JAWS and braille module.This research was conducted at MAN Maguwoharjo Yogyakarta involving 5 blind students in the chemistry subject of academic year 2013/2014. One student is as an instrument validation test subject, two students as subjects in the experimental class and two students as subjects in the control class. The instruments used in this study are the observation sheet,multiple choice test, questionnaire responses, motivation scale, and independent learning scale. Data of student achievement, motivation and independence scale were analyzed using nonparametric statistical test of independent samples. The result shows that no significant difference between the achievement, motivation, and independence of blind students who use screen reader JAWS module and braille module.

Concomitant administration of fluoxetine and amantadine modulates the activity of peritoneal macrophages of rats subjected to a forced swimming test.

Science.gov (United States)

Roman, Adam; Rogóz, Zofia; Kubera, Marta; Nawrat, Dominika; Nalepa, Irena

2009-01-01

Recent studies show that administration of a non-competitive NMDA receptor antagonist, amantadine (AMA), potentiates the action of antidepressant drugs. Since antidepressants may modulate functioning of the immune system and activation of a pro-inflammatory response in depressive disorders is frequently reported, the aim of the present study was to examine whether a combined administration of AMA and the antidepressant, fluoxetine (FLU), to rats subsequently subjected to a forced swimming test (FST) modifies the parameters of macrophage activity, directly related to their immunomodulatory functions, i.e., arginase (ARG) activity and synthesis of nitric oxide (NO). We found that 10 mg/kg AMA and 10 mg/kg FLU, ineffective in FST for antidepressant-like activity when administered alone, increased the ARG/NO ratio in macrophages when administered concomitantly. This effect was accompanied by a decrease of cellular adherence. Concurrently, the basal metabolic activity of the cells measured with reduction of resazurin, and intracellular host defense as assessed by a synthesis of superoxide anion, were not affected by such antidepressive treatment. Our data indicate that co-administration of AMA and FLU decreases the pro-inflammatory properties of macrophages and causes a redirection of immune response toward anti-inflammatory activity, as one can anticipate in the case of an effective antidepressive treatment.

Electrical Brain Responses to an Auditory Illusion and the Impact of Musical Expertise.

Science.gov (United States)

Ioannou, Christos I; Pereda, Ernesto; Lindsen, Job P; Bhattacharya, Joydeep

2015-01-01

The presentation of two sinusoidal tones, one to each ear, with a slight frequency mismatch yields an auditory illusion of a beating frequency equal to the frequency difference between the two tones; this is known as binaural beat (BB). The effect of brief BB stimulation on scalp EEG is not conclusively demonstrated. Further, no studies have examined the impact of musical training associated with BB stimulation, yet musicians' brains are often associated with enhanced auditory processing. In this study, we analysed EEG brain responses from two groups, musicians and non-musicians, when stimulated by short presentation (1 min) of binaural beats with beat frequency varying from 1 Hz to 48 Hz. We focused our analysis on alpha and gamma band EEG signals, and they were analysed in terms of spectral power, and functional connectivity as measured by two phase synchrony based measures, phase locking value and phase lag index. Finally, these measures were used to characterize the degree of centrality, segregation and integration of the functional brain network. We found that beat frequencies belonging to alpha band produced the most significant steady-state responses across groups. Further, processing of low frequency (delta, theta, alpha) binaural beats had significant impact on cortical network patterns in the alpha band oscillations. Altogether these results provide a neurophysiological account of cortical responses to BB stimulation at varying frequencies, and demonstrate a modulation of cortico-cortical connectivity in musicians' brains, and further suggest a kind of neuronal entrainment of a linear and nonlinear relationship to the beating frequencies.

Electrical Brain Responses to an Auditory Illusion and the Impact of Musical Expertise.

Directory of Open Access Journals (Sweden)

Christos I Ioannou

Full Text Available The presentation of two sinusoidal tones, one to each ear, with a slight frequency mismatch yields an auditory illusion of a beating frequency equal to the frequency difference between the two tones; this is known as binaural beat (BB. The effect of brief BB stimulation on scalp EEG is not conclusively demonstrated. Further, no studies have examined the impact of musical training associated with BB stimulation, yet musicians' brains are often associated with enhanced auditory processing. In this study, we analysed EEG brain responses from two groups, musicians and non-musicians, when stimulated by short presentation (1 min of binaural beats with beat frequency varying from 1 Hz to 48 Hz. We focused our analysis on alpha and gamma band EEG signals, and they were analysed in terms of spectral power, and functional connectivity as measured by two phase synchrony based measures, phase locking value and phase lag index. Finally, these measures were used to characterize the degree of centrality, segregation and integration of the functional brain network. We found that beat frequencies belonging to alpha band produced the most significant steady-state responses across groups. Further, processing of low frequency (delta, theta, alpha binaural beats had significant impact on cortical network patterns in the alpha band oscillations. Altogether these results provide a neurophysiological account of cortical responses to BB stimulation at varying frequencies, and demonstrate a modulation of cortico-cortical connectivity in musicians' brains, and further suggest a kind of neuronal entrainment of a linear and nonlinear relationship to the beating frequencies.

[Effects of long-term Tai Ji Quan exercise on automatic nervous modulation in the elderly].

Science.gov (United States)

Guo, Feng

2015-03-01

To examine the effects of long-term Tai Ji Quan (Chinnese Traditional Exercise) on automatic nervous modulation in the elders. The 18 subjects from Tai Ji Quan exercise class in Liaoning University of Retired Veteran Cadres were assigned into long-term Tai Ji Quan exercise group including 10 subjects and novice group including 8 subjects. Electrocardiography, respiratory and blood pressure data were collected on the following time points: at rest before Tai Ji Qhuan exercise and 30 min or 60 min after Tai Ji Quan exercise. The subjects at rest state in the long-term Tai Ji Quan exercise group showed higher than the subjects in the novice group in resperitory rate (RR), standard deviations of normal to normal intervals (SDNN), total power (TP), low frequency power (LFP), high frequency power (HFP), normalized high frequency power (nHFP), but lower in LFP/HFP, systolic and diastolic blood pressure, and heart rate. At rest state the respiratory rate of subjects in long-term Tai Ji Quan exercise group was significantly lower than the novices. After Tai Ji Quan exercise, TP, nHFP, LFP/HFP, heart rate and systolic pressure showed significantly changes, and the change level of Tai Ji Quan on these indices was larger in Tai Ji Quan exercise group than that in the novice group. Long-term Tai Ji Quan exercise can improve vagal modulations, and tend to reduce the sympathetic modulations.

Markers of liver function and inflammatory cytokines modulation by ...

African Journals Online (AJOL)

Conclusion: Aerobic exercise training modulates inflammatory cytokine levels and markers of liver function in patients with nonalcoholic ... and is associated with over nutrition and under activity, ... of these subjects with leptin reduced liver fat and liver enzyme ... tissue, muscle-released interleukin-6 inhibition of tumor.

Pressure Physiology: Studies of Acute and Chronic Exposures to Increased Pressures of Oxygen and Inert Gases in Diving, Decompression and Therapy of Decompression and Isobaric Gas Lesion Diseases

Science.gov (United States)

1985-12-31

puretone threshold at ultra-audiometric frequencies (10,000-20,000 Hz; e) Masking Level Differences (MLD) used to assess binaural processing in the auditory...SD in 5 Supine Resting Subjects) I Pre-exposure Mean Exposure Time Control 2.6 Hours 9.8 Hours I Heart Rate 59.8 + 10.7 50.2 + 8.5 63.6* + 14.4 ( beats ...complete absence of ectopic beats by 6 hours post-exposure. 72 FIGURE 26. 1 HEART RATE RESPONSES TO RISING FROM SUPINE TO STANDING POSITION IN SUBJECT (C.H

Dental students' evaluation of 2 community-oriented PBL modules.

Science.gov (United States)

Pau, A K; Collinson, S; Croucher, R

1999-11-01

To evaluate dental students' perception of 2 problem-based learning (PBL) modules in Dental Public Health implemented within the context of a traditional formal curriculum. 2 dental community modules were implemented with an 8-month interval between them on the same group of dental undergraduates; the first in Term 2 and the second in Term 4 of a 5-year 15-term dental course. At the end of each module, a semi-structured questionnaire was administered to evaluate the introductory lecture, the fieldwork activity and the organisation of the modules. In both modules, students reported gaining insight into the subject matter, skills in teamwork, making presentations and collecting data. Some students in the 1st module needed more time to fulfil their learning objectives and had difficulty in collecting data. In the 2nd module, students reported that they lacked motivation because of the place of the module within their timetable. Opinions differed about groupwork. The content of and interest generated by fieldwork activity was rated more positively in the 2nd module than the 1st. Less positively rated in the 2nd module was the introductory lecture and module organisation. Implementing PBL within a traditional curriculum does not offer uniform outcomes for students. Optimum group size and adequate time are necessary if students are to benefit from PBL. A consistent and continuous PBL approach should be adopted rather than a sporadic one. Further research should establish the optimum balance between PBL and traditional approaches that would allow students to maximise the benefits of both and to identify those students best equipped to benefit from a 'mixed economy' of learning.

Changes in soleus H-reflex during walking in middle-aged, healthy subjects

DEFF Research Database (Denmark)

Raffalt, Peter C; Alkjær, Tine; Simonsen, Erik B

2015-01-01

INTRODUCTION: To assess the effect of aging on stretch reflex modulation during walking, soleus H-reflexes obtained in 15 middle-aged (mean age 56.4±6.9 years) and 15 young (mean age 23.7±3.9 years) subjects were compared. METHODS: The H-reflex amplitude, muscle activity (EMG) of the soleus...... and tibialis anterior muscles, and EMG/H-reflex gain were measured during 4-km/h treadmill walking. RESULTS: The normalized H-reflex amplitude was lower in the swing phase for the middle-aged group, and there was no difference in muscle activity. EMG/H-reflex gain did not differ between groups. CONCLUSIONS: H......-reflex amplitude during walking was affected by aging, and changes during the swing phase could be seen in the middle-aged subjects. Subdividing the 2 age groups into groups of facilitated or suppressed swing-phase H-reflex revealed that the H-reflex amplitude modulation pattern in the group with facilitated swing...

Wheat bran cereal, human gut bacteria and subjective wellbeing

OpenAIRE

Smith, Andrew; Deaville, Eddie; Gibson, Glenn

2018-01-01

Research has shown that consumption of high fiber breakfast cereal is associated with improved subjective well-being, especially increased energy. One possible explanation of these results is through metabolism by gut bacteria and concomitant production of metabolites that influence psychological and gastrointestinal (GI) welfare. This was examined in the present study to determine whether consumption of wheat bran could modulate the composition of the GI microbiota. This human volunteer stud...

Photovoltaic module and interlocked stack of photovoltaic modules

Science.gov (United States)

Wares, Brian S.

2014-09-02

One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame. A plurality of individual male alignment features and a plurality of individual female alignment features are included on each frame. Adjacent photovoltaic modules are interlocked by multiple individual male alignment features on a first module of the adjacent photovoltaic modules fitting into and being surrounded by corresponding individual female alignment features on a second module of the adjacent photovoltaic modules. Other embodiments, features and aspects are also disclosed.

Auditory steady-state responses in cochlear implant users: Effect of modulation frequency and stimulation artifacts.

Science.gov (United States)

Gransier, Robin; Deprez, Hanne; Hofmann, Michael; Moonen, Marc; van Wieringen, Astrid; Wouters, Jan

2016-05-01

Previous studies have shown that objective measures based on stimulation with low-rate pulse trains fail to predict the threshold levels of cochlear implant (CI) users for high-rate pulse trains, as used in clinical devices. Electrically evoked auditory steady-state responses (EASSRs) can be elicited by modulated high-rate pulse trains, and can potentially be used to objectively determine threshold levels of CI users. The responsiveness of the auditory pathway of profoundly hearing-impaired CI users to modulation frequencies is, however, not known. In the present study we investigated the responsiveness of the auditory pathway of CI users to a monopolar 500 pulses per second (pps) pulse train modulated between 1 and 100 Hz. EASSRs to forty-three modulation frequencies, elicited at the subject's maximum comfort level, were recorded by means of electroencephalography. Stimulation artifacts were removed by a linear interpolation between a pre- and post-stimulus sample (i.e., blanking). The phase delay across modulation frequencies was used to differentiate between the neural response and a possible residual stimulation artifact after blanking. Stimulation artifacts were longer than the inter-pulse interval of the 500pps pulse train for recording electrodes ipsilateral to the CI. As a result the stimulation artifacts could not be removed by artifact removal on the bases of linear interpolation for recording electrodes ipsilateral to the CI. However, artifact-free responses could be obtained in all subjects from recording electrodes contralateral to the CI, when subject specific reference electrodes (Cz or Fpz) were used. EASSRs to modulation frequencies within the 30-50 Hz range resulted in significant responses in all subjects. Only a small number of significant responses could be obtained, during a measurement period of 5 min, that originate from the brain stem (i.e., modulation frequencies in the 80-100 Hz range). This reduced synchronized activity of brain stem

Pengembangan Modul Bimbingan dan Konseling untuk Pencegahan Penyalahgunaan Narkoba di Sekolah

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Rani Mega Putri

2014-01-01

Full Text Available The problem of drug abuse has penetrated up to the world of education, including SMP. Many ways that could be used by guidance and counseling teachers or counselors to enhance students' understanding of the dangers of drug abuse, one of them by using the media as an exciting learning modules. Module was one of tools that addresses learning about a subject systematically arranged and sequentially to facilitate students achieve and master a targeted competencies along with guidelines for the use of teachers. This study aimed: (1 to formulate guidance and counseling module for drug abuse prevention in school-appropriate content to be used by guidance and counseling teacher or counselor, and (2 to describe the level of applicability formulation guidance and counseling module for drug abuse prevention in school by guidance and counseling teacher or counselor. This research was conducted using development research methods, with guided model development step ADDIE (Analyze, Design, Development, Implementation, and Evaluation. The subjects of the trial research were (1 the content expert, and (2 the target users of the product, was guidance and counseling teacher or counselor, who was taken by using purposive sampling method, in order to obtain test subjects research, namely 3 content experts, and 3 people guidance and counseling teacher or counselor. This study was conducted with a limited research product tested and the data was analyzed descriptively. The results of the research showed that: (1 guidance and counseling module to prevent drug abuse, as a content was very feasible for used by students and guidance and counseling teachers or counselors in implementation of service, (2 the level of guidance module and counseling applicability to prevent of drug abuse rated very high for used by students. Based on these results of the research, generally, it could be concluded that the research products produced were feasible and could be used to help

Dynamics of simple magnetorheological suspensions under rotating magnetic fields with modulated Mason number

International Nuclear Information System (INIS)

Calderon, Oscar G; Melle, Sonia

2002-01-01

We study theoretically the dynamics of a system of two magnetizable particles suspended in a non-magnetic fluid subject to a rotating magnetic field when a modulation on the Mason number (ratio of viscous to magnetic forces) is applied. We find, using a periodic modulation, that a resonant-like phenomenon between the periodic modulation of the Mason number and the intrinsic radial oscillation of the system without modulation occurs. For a random perturbation of the Mason number, we obtain an optimum noise strength at which the average interparticle distance reaches the lowest value. When a weak periodic modulation and a noise source are included in the Mason number, stochastic resonance (SR) is found for different frequencies and amplitudes of the modulation. An interpretation of this SR phenomenon is made by means of a threshold crossing mechanism

Characterization of Cu(In,Ga)Se2 photovoltaic modules

International Nuclear Information System (INIS)

Dyk, E.E. van; Radue, C.; Gxasheka, A.R.

2007-01-01

In this study copper indium gallium diselenide photovoltaic (PV) modules were subjected to a thorough indoor assessment procedure. The assessment is to be used as a baseline for future evaluation of the modules deployed outdoors as part of an ongoing evaluation of device performance and degradation. The main focus of the study is the long term monitoring of the devices to determine service lifetime. In this paper we will present initial results of the baseline evaluation, namely I-V characteristics, thorough visual inspection and an analysis of performance parameters. The results obtained revealed that the performance of one of the modules was inferior to the others evaluated. In order to further investigate this, laser beam induced current (LBIC) measurements were conducted on regions that had a non-uniform appearance as observed visually

Weyl modules, demazure modules, KR-modules, crystals, fusion products and limit constructions

OpenAIRE

Fourier, G.; Littelmann, P.

2007-01-01

We study finite dimensional representations of current algebras, loop algebras and their quantized versions. For the current algebra of a simple Lie algebra of type {\\tt ADE}, we show that Kirillov-Reshetikhin modules and Weyl modules are in fact all Demazure modules. As a consequence one obtains an elementary proof of the dimension formula for Weyl modules for the current and the loop algebra. Further, we show that the crystals of the Weyl and the Demazure module are the same up to some addi...

Superstability for Generalized Module Left Derivations and Generalized Module Derivations on a Banach Module (I

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Rassias JM

2009-01-01

Full Text Available We discuss the superstability of generalized module left derivations and generalized module derivations on a Banach module. Let be a Banach algebra and a Banach -module, and . The mappings , and are defined and it is proved that if (resp., is dominated by then is a generalized (resp., linear module- left derivation and is a (resp., linear module- left derivation. It is also shown that if (resp., is dominated by then is a generalized (resp., linear module- derivation and is a (resp., linear module- derivation.

Anodal Transcranial Direct Current Stimulation Promotes Frontal Compensatory Mechanisms in Healthy Elderly Subjects.

Science.gov (United States)

Cespón, Jesús; Rodella, Claudia; Rossini, Paolo M; Miniussi, Carlo; Pellicciari, Maria C

2017-01-01

Recent studies have demonstrated that transcranial direct current stimulation (tDCS) is potentially useful to improve working memory. In the present study, young and elderly subjects performed a working memory task ( n -back task) during an electroencephalogram recording before and after receiving anodal, cathodal, and sham tDCS over the left dorsolateral prefrontal cortex (DLPFC). We investigated modulations of behavioral performance and electrophysiological correlates of working memory processes (frontal and parietal P300 event-related potentials). A strong tendency to modulated working memory performance was observed after the application of tDCS. In detail, young, but not elderly, subjects benefited from additional practice in the absence of real tDCS, as indicated by their more accurate responses after sham tDCS. The cathodal tDCS had no effect in any group of participants. Importantly, anodal tDCS improved accuracy in elderly. Moreover, increased accuracy after anodal tDCS was correlated with a larger frontal P300 amplitude. These findings suggest that, in elderly subjects, improved working memory after anodal tDCS applied over the left DLPFC may be related to the promotion of frontal compensatory mechanisms, which are related to attentional processes.

Anodal Transcranial Direct Current Stimulation Promotes Frontal Compensatory Mechanisms in Healthy Elderly Subjects

Directory of Open Access Journals (Sweden)

Jesús Cespón

2017-12-01

Full Text Available Recent studies have demonstrated that transcranial direct current stimulation (tDCS is potentially useful to improve working memory. In the present study, young and elderly subjects performed a working memory task (n-back task during an electroencephalogram recording before and after receiving anodal, cathodal, and sham tDCS over the left dorsolateral prefrontal cortex (DLPFC. We investigated modulations of behavioral performance and electrophysiological correlates of working memory processes (frontal and parietal P300 event-related potentials. A strong tendency to modulated working memory performance was observed after the application of tDCS. In detail, young, but not elderly, subjects benefited from additional practice in the absence of real tDCS, as indicated by their more accurate responses after sham tDCS. The cathodal tDCS had no effect in any group of participants. Importantly, anodal tDCS improved accuracy in elderly. Moreover, increased accuracy after anodal tDCS was correlated with a larger frontal P300 amplitude. These findings suggest that, in elderly subjects, improved working memory after anodal tDCS applied over the left DLPFC may be related to the promotion of frontal compensatory mechanisms, which are related to attentional processes.

Dosimetry computer module of the gamma irradiator of ININ

International Nuclear Information System (INIS)

Ledezma F, L. E.; Baldomero J, R.; Agis E, K. A.

2012-10-01

This work present the technical specifications for the upgrade of the dosimetry module of the computer system of the gamma irradiator of the Instituto Nacional de Investigaciones Nucleares (ININ) whose result allows the integration and consultation of information in industrial dosimetry subject under an outline client-server. (Author)

Beta receptor-mediated modulation of the late positive potential in humans.

Science.gov (United States)

de Rover, Mischa; Brown, Stephen B R E; Boot, Nathalie; Hajcak, Greg; van Noorden, Martijn S; van der Wee, Nic J A; Nieuwenhuis, Sander

2012-02-01

Electrophysiological studies have identified a scalp potential, the late positive potential (LPP), which is modulated by the emotional intensity of observed stimuli. Previous work has shown that the LPP reflects the modulation of activity in extrastriate visual cortical structures, but little is known about the source of that modulation. The present study investigated whether beta-adrenergic receptors are involved in the generation of the LPP. We used a genetic individual differences approach (experiment 1) and a pharmacological manipulation (experiment 2) to test the hypothesis that the LPP is modulated by the activation of β-adrenergic receptors. In experiment 1, we found that LPP amplitude depends on allelic variation in the β1-receptor gene polymorphism. In experiment 2, we found that LPP amplitude was modulated by the β-blocker propranolol in a direction dependent on subjects' level of trait anxiety: In participants with lower trait anxiety, propranolol led to a (nonsignificant) decrease in the LPP modulation; in participants with higher trait anxiety, propranolol increased the emotion-related LPP modulation. These results provide initial support for the hypothesis that the LPP reflects the downstream effects, in visual cortical areas, of β-receptor-mediated activation of the amygdala.

Factors affecting perception thresholds of vertical whole-body vibration in recumbent subjects: Gender and age of subjects, and vibration duration

Science.gov (United States)

Matsumoto, Y.; Maeda, S.; Iwane, Y.; Iwata, Y.

2011-04-01

Some factors that may affect human perception thresholds of the vertical whole-body vibrations were investigated in two laboratory experiments with recumbent subjects. In the first experiment, the effects of gender and age of subjects on perception were investigated with three groups of 12 subjects, i.e., young males, young females and old males. For continuous sinusoidal vibrations at 2, 4, 8, 16, 31.5 and 63 Hz, there were no significant differences in the perception thresholds between male and female subjects, while the thresholds of young subjects tended to be significantly lower than the thresholds of old subjects. In the second experiment, the effect of vibration duration was investigated by using sinusoidal vibrations, at the same frequencies as above, modulated by the Hanning windows with different lengths (i.e., 0.5, 1.0, 2.0 and 4.0 s) for 12 subjects. It was found that the peak acceleration at the threshold tended to decrease with increasing duration of vibration. The perception thresholds were also evaluated by the running root-mean-square (rms) acceleration and the fourth power acceleration method defined in the current standards. The differences in the threshold of the transient vibrations for different durations were less with the fourth power acceleration method. Additionally, the effect of the integration time on the threshold was investigated for the running rms acceleration and the fourth power acceleration. It was found that the integration time that yielded less differences in the threshold of vibrations for different durations depended on the frequency of vibration.

Control channels in the brain and their influence on brain executive functions

Science.gov (United States)

Meng, Qinglei; Choa, Fow-Sen; Hong, Elliot; Wang, Zhiguang; Islam, Mohammad

2014-05-01

In a computer network there are distinct data channels and control channels where massive amount of visual information are transported through data channels but the information streams are routed and controlled by intelligent algorithm through "control channels". Recent studies on cognition and consciousness have shown that the brain control channels are closely related to the brainwave beta (14-40 Hz) and alpha (7-13 Hz) oscillations. The high-beta wave is used by brain to synchronize local neural activities and the alpha oscillation is for desynchronization. When two sensory inputs are simultaneously presented to a person, the high-beta is used to select one of the inputs and the alpha is used to deselect the other so that only one input will get the attention. In this work we demonstrated that we can scan a person's brain using binaural beats technique and identify the individual's preferred control channels. The identified control channels can then be used to influence the subject's brain executive functions. In the experiment, an EEG measurement system was used to record and identify a subject's control channels. After these channels were identified, the subject was asked to do Stroop tests. Binaural beats was again used to produce these control-channel frequencies on the subject's brain when we recorded the completion time of each test. We found that the high-beta signal indeed speeded up the subject's executive function performance and reduced the time to complete incongruent tests, while the alpha signal didn't seem to be able to slow down the executive function performance.

Modulation of walking speed by changing optic flow in persons with stroke

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Lamontagne Anouk