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Sample records for switch-mode audio power

  1. Switching-mode Audio Power Amplifiers with Direct Energy Conversion

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    has been replaced with a high frequency AC link. When compared to the conventional Class D amplifiers with a separate DC power supply, the proposed single conversion stage amplifier provides simple and compact solution with better efficiency and higher level of integration, leading to reduced......This paper presents a new class of switching-mode audio power amplifiers, which are capable of direct energy conversion from the AC mains to the audio output. They represent an ultimate integration of a switching-mode power supply and a Class D audio power amplifier, where the intermediate DC bus...

  2. Multi Carrier Modulator for Switch-Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael Andreas E.

    2008-01-01

    While switch-mode audio power amplifiers allow compact implementations and high output power levels due to their high power efficiency, they are very well known for creating electromagnetic interference (EMI) with other electronic equipment, in particular radio receivers. Lowering the EMI of switch......-mode audio power amplifiers while keeping the performance measures to excellent levels is therefore of high general interest. A modulator utilizing multiple carrier signals to generate a two level pulse train will be shown in this paper. The performance of the modulator will be compared in simulation...

  3. Current-Driven Switch-Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Buhl, Niels Christian; Andersen, Michael A. E.

    2012-01-01

    The conversion of electrical energy into sound waves by electromechanical transducers is proportional to the current through the coil of the transducer. However virtually all audio power amplifiers provide a controlled voltage through the interface to the transducer. This paper is presenting...... a switch-mode audio power amplifier not only providing controlled current but also being supplied by current. This results in an output filter size reduction by a factor of 6. The implemented prototype shows decent audio performance with THD + N below 0.1 %....

  4. Minimizing Crosstalk in Self Oscillating Switch Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Ploug, Rasmus Overgaard

    2012-01-01

    The varying switching frequencies of self oscillating switch mode audio amplifiers have been known to cause interchannel intermodulation disturbances in multi channel configurations. This crosstalk phenomenon has a negative impact on the audio performance. The goal of this paper is to present...... by the implementation presented. Future work could include further refinement of the implementation of the concepts, electromagnetic interference investigations or PCB design....

  5. Efficiency of Switch-Mode Power Audio Amplifiers - Test Signals and Measurement Techniques

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Knott, Arnold; Andersen, Michael A. E.

    2016-01-01

    Switch-mode technology is greatly used for audio amplification. This is mainly due to the great efficiency this technology offers. Normally the efficiency of a switch-mode audio amplifier is measured using a sine wave input. However this paper shows that sine waves represent real audio very poorly....... An alternative signal is proposed for test purposes. The efficiency of a switch-mode power audio amplifier is modelled and measured with both sine wave and the proposed test signal as inputs. The results show that the choice of switching devices with low on resistances are unfairly favored when measuring...

  6. Multilevel tracking power supply for switch-mode audio power amplifiers

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Lazarevic, Vladan; Vasic, Miroslav

    2018-01-01

    Switch-mode technology is the common choice for high efficiency audio power amplifiers. The dynamic nature of real audio reduces efficiency as less continuous output power can be achieved. Based on methods used for RF amplifiers this paper proposes to employ envelope tracking techniques...

  7. GaN Power Stage for Switch-mode Audio Amplification

    DEFF Research Database (Denmark)

    Ploug, Rasmus Overgaard; Knott, Arnold; Poulsen, Søren Bang

    2015-01-01

    N FETs. This project seeks to investigate the possibilities of using eGaN FETs as the power switching device in a full bridge power stage intended for switch mode audio amplification. A 50 W 1 MHz power stage was built and provided promising audio performance. Future work includes optimization of dead...... time and investigation of switching frequency versus audio performance....

  8. Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify design, increase efficiency and integration level, reduce product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented. (au)

  9. Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify the design, increase effic...... efficiency, reduce the product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented....

  10. GaN Power Stage for Switch-mode Audio Amplification

    DEFF Research Database (Denmark)

    Ploug, Rasmus Overgaard; Knott, Arnold; Poulsen, Søren Bang

    2015-01-01

    Gallium Nitride (GaN) based power transistors are gaining more and more attention since the introduction of the enhancement mode eGaN Field Effect Transistor (FET) which makes an adaptation from Metal-Oxide Semiconductor (MOSFET) to eGaN based technology less complex than by using depletion mode Ga......N FETs. This project seeks to investigate the possibilities of using eGaN FETs as the power switching device in a full bridge power stage intended for switch mode audio amplification. A 50 W 1 MHz power stage was built and provided promising audio performance. Future work includes optimization of dead...

  11. Integrating switch mode audio power amplifiers and electro dynamic loudspeakers for a higher power efficiency

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier.......The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier....

  12. Practical considerations for integrating switch mode audio amplifiers and loudspeakers for a higher power efficiency

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    An integration of electrodynamic loudspeakers and switch mode amplifiers has earlier been proposed in [1]. The work presented in this paper is related to the practical aspects of integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker’s voice coil as output...... filter, and the magnetic structure as heat sink for the amplifier....

  13. Active Electromagnetic Interference Cancelation for Automotive Switch-Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael A. E.

    2009-01-01

    Recent trends in the automotive audio industry have shown the importance of active noise cancelation (ANC) for major improvements in mobile entertainment environments. These approaches target the acoustical noise in the cabin and superimpose an inverse noise signal to cancel disturbances. Electro......Recent trends in the automotive audio industry have shown the importance of active noise cancelation (ANC) for major improvements in mobile entertainment environments. These approaches target the acoustical noise in the cabin and superimpose an inverse noise signal to cancel disturbances...... in simulation and experiment. The resulting switch-mode audio power amplifier of this experiment keeps its high efficiency and is able to deliver the signal with less than 0.1 % distortion, while improving the source of electromagnetic interference by 15 dB....

  14. Integrating switch mode audio amplifiers and electro dynamic loudspeakers for a higher power efficiency

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier.......The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier....

  15. Comparison of Power Supply Pumping of Switch-Mode Audio Power Amplifiers with Resistive Loads and Loudspeakers as Loads

    DEFF Research Database (Denmark)

    Knott, Arnold; Petersen, Lars Press

    2013-01-01

    Power supply pumping is generated by switch-mode audio power amplifiers in half-bridge configuration, when they are driving energy back into their source. This leads in most designs to a rising rail voltage and can be destructive for either the decoupling capacitors, the rectifier diodes...... in the power supply or the power stage of the amplifier. Therefore precautions are taken by the amplifier and power supply designer to avoid those effects. Existing power supply pumping models are based on an ohmic load attached to the amplifier. This paper shows the analytical derivation of the resulting...

  16. Investigation of crosstalk in self oscillating switch mode audio power amplifier

    DEFF Research Database (Denmark)

    Birch, Thomas Haagen; Ploug, Rasmus Overgaard; Iversen, Niels Elkjær

    2012-01-01

    Self oscillating switch mode power ampliers are known to be susceptible to interchannel disturbances also known as crosstalk. This phenomenon has a signicant impact on the performance of an amplier of this type. The goal of this paper is to investigate the presence and origins of crosstalk in a t...

  17. Switch mode power supply

    International Nuclear Information System (INIS)

    Kim, Hui Jun

    1993-06-01

    This book concentrates on switch mode power supply. It has four parts, which are introduction of switch mode power supply with DC-DC converter such as Buck converter boost converter, Buck-boost converter and PWM control circuit, explanation for SMPS with DC-DC converter modeling and power mode control, resonance converter like resonance switch, converter, multi resonance converter and series resonance and parallel resonance converters, basic test of SMPS with PWM control circuit, Buck converter, Boost converter, flyback converter, forward converter and IC for control circuit.

  18. Approaches to building single-stage AC/AC conversion switch-mode audio power amplifiers

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2004-01-01

    This paper discusses the possible topologies and promising approaches towards direct single-phase AC-AC conversion of the mains voltage for audio applications. When compared to standard Class-D switching audio power amplifiers with a separate power supply, it is expected that direct conversion...

  19. Approaches to building single-stage AC/AC conversion switch-mode audio power amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    This paper discusses the possible topologies and promising approaches towards direct single-phase AC-AC conversion of the mains voltage for audio applications. When compared to standard Class-D switching audio power amplifiers with a separate power supply, it is expected that direct conversion will provide better efficiency and higher level of integration, leading to lower component count, volume and cost, but at the expense of a minor performance deterioration. (au)

  20. Power quality improvement in switched mode power supplies using ...

    African Journals Online (AJOL)

    user

    In view of these issues, this investigation deals with the design and control of an improved power quality switched mode power ... A SEPIC stores the energy in an inductor, and transfers that energy to the output storage capacitor. This energy is released through the secondary windings when the switch Sw2 is turned off.

  1. Analisys of Current-Bidirectional Buck-Boost Based Automotive Switch-Mode Audio Amplifier

    DEFF Research Database (Denmark)

    Bolten Maizonave, Gert; Andersen, Michael A. E.; Kjærgaard, Claus

    2011-01-01

    The following study was carried out in order to assess quantitatively the performance of the buck-boost converter when used as switch-mode audio amplifier. It comprises of, to begin with, the delimitation of design criteria based on the state-ofthe- art solution, which is based in a differential ...

  2. Efficient audio power amplification - challenges

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Michael A.E.

    2005-07-01

    For more than a decade efficient audio power amplification has evolved and today switch-mode audio power amplification in various forms are the state-of-the-art. The technical steps that lead to this evolution are described and in addition many of the challenges still to be faced and where extensive research and development are needed is covered. (au)

  3. Efficient Audio Power Amplification - Challenges

    DEFF Research Database (Denmark)

    Andersen, Michael Andreas E.

    2005-01-01

    For more than a decade efficient audio power amplification has evolved and today switch-mode audio power amplification in various forms are the state-of-the-art. The technical steps that lead to this evolution are described and in addition many of the challenges still to be faced and where...... extensive research and development are needed is covered....

  4. Very High Frequency Switch-Mode Power Supplies

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre

    of technologies for very high frequency switch mode power supplies. At these highly elevated frequencies normal bulky magnetics with heavy cores consisting of rare earth materials, can be replaced by air core inductors embedded in the printed circuit board. This is investigated thoroughly and both spirals......, solenoids and toroids are considered, both for use as inductors and transformers. Two control methods are also investigated, namely burst mode control and outphasing. It is shown that a very flat efficiency curve can be achieved with burst mode. A 89.5% efficient converter is implemented and the efficiency...

  5. 275 C Downhole Switched-Mode Power Supply

    Energy Technology Data Exchange (ETDEWEB)

    Chris Hutchens; Vijay Madhuravasal

    2008-08-31

    A vee-square (V2) control based controller IC is developed for a switch mode power supply capable of operating at extreme temperature/harsh environment conditions. A buck type regulator with silicon carbide power junction field effect transistors (JFET) as power devices is used to analyze the performance of controller. Special emphases are made on the analog sub-blocks--voltage reference, operational transconductance amplifier and comparator as individual building blocks. Transformer coupled gate drives and high temperature operable magnetic cores and capacitors are identified and tested for use in the design. Conventional ceramic chip packaging of ICs combined with lead carrier type mounting of passive filter components is introduced for hybrid packaging of the complete product. The developed SMPS is anticipated to support the operation of down-hole microcontrollers and other electronics devices that require low/medium power filtered dc inputs over an operating temperature of 275 C.

  6. S-band class-F power amplifier with integrated switched mode power supply

    NARCIS (Netherlands)

    Bent, G. van der; Hek, A.P. de; Geurts, S.; Brouzes, H.; Vliet, F.E. van

    2012-01-01

    An S-band radar transmitter MMIC is reported containing a class-F power amplifier and a switched mode power supply. The integration of the power supply offers the possibility to optimize the power amplifier bias voltage for each individual device in a AESA antenna. This has several advantages such

  7. A Switching-Mode Power Supply Design Tool to Improve Learning in a Power Electronics Course

    Science.gov (United States)

    Miaja, P. F.; Lamar, D. G.; de Azpeitia, M.; Rodriguez, A.; Rodriguez, M.; Hernando, M. M.

    2011-01-01

    The static design of ac/dc and dc/dc switching-mode power supplies (SMPS) relies on a simple but repetitive process. Although specific spreadsheets, available in various computer-aided design (CAD) programs, are widely used, they are difficult to use in educational applications. In this paper, a graphic tool programmed in MATLAB is presented,…

  8. Digital control of high-frequency switched-mode power converters

    CERN Document Server

    Corradini, Luca; Mattavelli, Paolo; Zane, Regan

    This book is focused on the fundamental aspects of analysis, modeling and design of digital control loops around high-frequency switched-mode power converters in a systematic and rigorous manner Comprehensive treatment of digital control theory for power converters Verilog and VHDL sample codes are provided Enables readers to successfully analyze, model, design, and implement voltage, current, or multi-loop digital feedback loops around switched-mode power converters Practical examples are used throughout the book to illustrate applications of the techniques developed Matlab examples are also

  9. Multi Carrier Modulation Audio Power Amplifier with Programmable Logic

    DEFF Research Database (Denmark)

    Christiansen, Theis; Andersen, Toke Meyer; Knott, Arnold

    2009-01-01

    While switch-mode audio power amplifiers allow compact implementations and high output power levels due to their high power efficiency, they are very well known for creating electromagnetic interference (EMI) with other electronic equipment. To lower the EMI of switch-mode (class D) audio power...... for performance and out of band spectral amplitudes. The basic principle in MCM is to use programmable logic to combine two or more Pulse Width Modulated (PWM) audio signals at different switching frequencies. In this way the out of band spectrum will be lowered compared with conventional class D amplifiers...

  10. Analysis of current-bidirectional buck-boost based switch-mode audio amplifier

    DEFF Research Database (Denmark)

    Bolten Maizonave, Gert; Andersen, Michael A. E.; Kjærgaard, Claus

    2011-01-01

    The following studdy was carried out in order to assses quantitatively the performannce of the buck--boost converter whhen used as swiitch-mode audio amplifier. It comprises of, to beggin with, the de limitation of design criteria bassed on the state of-the-art solution, which is based in a diffe......The following studdy was carried out in order to assses quantitatively the performannce of the buck--boost converter whhen used as swiitch-mode audio amplifier. It comprises of, to beggin with, the de limitation of design criteria bassed on the state of-the-art solution, which is based...... in such configuration when applied for audio....

  11. [Design of a flyback switch mode power supply for multichannel electrophysiological stimulators].

    Science.gov (United States)

    Zhou, Yu; Fang, Zu-Xiang; Li, Wei-Jiao; Liu, Zu-Wang

    2008-05-01

    In order to supply the multichannel electrical stimulator, a DC-DC flyback switch mode power supply based on a high-performance current mode controller UC3845 has been designed. The experimental results indicate that the power supply has satisfied the demands and can supply the multichannel electrical stimulator and similar apparatuses.

  12. Integrated Very High Frequency Switch Mode Power Supplies: Design Considerations

    DEFF Research Database (Denmark)

    Hertel, Jens Christian; Nour, Yasser; Knott, Arnold

    2017-01-01

    This paper presents a power supply using an increased switching frequency to minimize the size of energy storing components, thereby addressing the demands for increased power densities in power supplies. 100 MHz and higher switching frequencies have been used in resonant power converters, which...... oscillating gate drive, presenting a future challenge for power supplies on chip....

  13. Generalized Simulation Model for a Switched-Mode Power Supply Design Course Using MATLAB/SIMULINK

    Science.gov (United States)

    Liao, Wei-Hsin; Wang, Shun-Chung; Liu, Yi-Hua

    2012-01-01

    Switched-mode power supplies (SMPS) are becoming an essential part of many electronic systems as the industry drives toward miniaturization and energy efficiency. However, practical SMPS design courses are seldom offered. In this paper, a generalized MATLAB/SIMULINK modeling technique is first presented. A proposed practical SMPS design course at…

  14. One-Quadrant Switched-Mode Power Converters

    CERN Document Server

    Petrocelli, R.

    2015-06-15

    This article presents the main topics related to one-quadrant power convert- ers. The basic topologies are analysed and a simple methodology to obtain the steady-state output–input voltage ratio is set out. A short discussion of dif- ferent methods to control one-quadrant power converters is presented. Some of the reported derived topologies of one-quadrant power converters are also considered. Some topics related to one-quadrant power converters such as syn- chronous rectification, hard and soft commutation, and interleaved converters are discussed. Finally, a brief introduction to resonant converters is given.

  15. State-of-the-art piezoelectric transformer-based switch mode power supplies

    DEFF Research Database (Denmark)

    Ekhtiari, Marzieh; Zhang, Zhe; Andersen, Michael A. E.

    2014-01-01

    rmers due to their smaller size, lighter weight, lower electromagn etic interference, higher power density, higher efficiency, and lower cost. Moreover, PTs allow converters to operate in high switching frequencies and by obtaining soft switching condition, switchin g losses will decrease. This paper...... discusses power supplies with the trend evaluation of piezoelectric transformer-based converter topologies and control methods. The challenges of piezoelectric transformers regarding soft switching capability and nonlinearity are addressed. This paper can be used as a guideline f or choosing a proper......Inductorless switch mode power supplies based on piezoelectric transformers are used to replace conventional transformers in high power density switch mode power supplies. Even though piezoelectric-based converters exhibit a high d egree of nonlinearity, it is desirable to use piezoelectric transfo...

  16. High Efficiency, High Linearity, Switch Mode Power Amplifiers for Varying envelop Signal Applications

    DEFF Research Database (Denmark)

    Tong, Tian; Sira, Daniel; Nielsen, Michael

    2009-01-01

    Transmission of big h-order modulated signals at sufficient linearity while maintaining high power efficiency is always a challenge in modern communication application. Using conventional transmitter topologies, high linearity and high efficiency are two conflicting parameters somehow. However...... using switch-mode power amplifier aided by various linearization techniques can present a feasible way to achieve both high linearity and high power efficiency. In this paper two different implementations of the switch-mode power amplifier a re p resented for varying envelop applications: the RF pulse...... width modulation technology and the outphasing configuration with SDR pre-distortion technology. The results presented show that all three solutions are capable of providing adequate performance....

  17. Design automation of switching mode high voltage power supply for nuclear instruments

    International Nuclear Information System (INIS)

    El-araby, S.M.S.

    1999-01-01

    This paper presents an automation procedure for the design of switching mode high voltage power supplies, using Pc programming facility. The procedure permits the selection of a ready made or designed ferrite transformer. This selection could be achieved according to the designer desire; as the program includes complete information about ready made ferrite transformer through complete database. The procedure is based on suggested template circuit. Micro-Cap IV simulation package is used to verify the desired high voltage power supply design. Simulation results agree quite well with suggested procedure's results. Design aspects and development needed to increase automation capabilities are also discussed

  18. Dynamic optimum dead time in piezoelectric transformer-based switch-mode power supplies

    DEFF Research Database (Denmark)

    Ekhtiari, Marzieh; Andersen, Thomas; Andersen, Michael A. E.

    2016-01-01

    Soft switching is required to attain high efficiency in high-frequency power converters. Piezoelectric transformerbased converters can benefit from soft switching in terms of significantly diminished switching losses and stresses. Adequate dead time is needed in order to deliver sufficient energy...... to charge and discharge the input capacitance of piezoelectric transformers in order to achieve zero-voltage switching. This paper proposes a method for detecting the optimum dead time in piezoelectric transformer-based switch-mode power supplies. The provision of sufficient dead time in every cycle...

  19. Self-oscillating modulators for direct energy conversion audio power amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    Direct energy conversion audio power amplifier represents total integration of switching-mode power supply and Class D audio power amplifier into one compact stage, achieving high efficiency, high level of integration, low component count and eventually low cost. This paper presents how self-oscillating modulators can be used with the direct switching-mode audio power amplifier to improve its performance by providing fast hysteretic control with high power supply rejection ratio, open-loop stability and high bandwidth. Its operation is thoroughly analyzed and simulated waveforms of a prototype amplifier are presented. (au)

  20. Self-oscillating modulators for direct energy conversion audio power amplifiers

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    Direct energy conversion audio power amplifier represents total integration of switching-mode power supply and Class D audio power amplifier into one compact stage, achieving high efficiency, high level of integration, low component count and eventually low cost. This paper presents how self......-oscillating modulators can be used with the direct switching-mode audio power amplifier to improve its performance by providing fast hysteretic control with high power supply rejection ratio, open-loop stability and high bandwidth. Its operation is thoroughly analyzed and experimental results from prototype amplifier...

  1. SWITCH MODE PULSE WIDTH MODULATED DC-DC CONVERTER WITH MULTIPLE POWER TRANSFORMERS

    DEFF Research Database (Denmark)

    2009-01-01

    A switch mode pulse width modulated DC-DC power converter comprises at least one first electronic circuit on a input side (1) and a second electronic circuit on a output side (2). The input side (1) and the output side (2) are coupled via at least two power transformers (T1, T2). Each power...... transformer (T1, T2) comprises a first winding (T1a, T2a) arranged in a input side converter stage (3, 4) on the input side (1) and a second winding (T1 b, T2b) arranged in a output side converter stage (5) on the output side (2), and each of the windings (T1a, T1 b, T2a, T2b) has a first end and a second end....... The first electronic circuit comprises terminals (AO, A1) for connecting a source or a load, at least one energy storage inductor (L) coupled in series with at least one of the first windings (T1a, T2a) of the power transformers (T1, T2), and for each power transformer (T1, T2), an arrangement of switches...

  2. Cable Insulation Breakdowns in the Modulator with a Switch Mode High Voltage Power Supply

    CERN Document Server

    Cours, A

    2004-01-01

    The Advanced Photon Source modulators are PFN-type pulsers with 40 kV switch mode charging power supplies (PSs). The PS and the PFN are connected to each other by 18 feet of high-voltage (HV) cable. Another HV cable connects two separate parts of the PFN. The cables are standard 75 kV x-ray cables. All four cable connectors were designed by the PS manufacturer. Both cables were operating at the same voltage level (about 35 kV). The PS’s output connector has never failed during five years of operation. One of the other three connectors failed approximately five times more often than the others. In order to resolve the failure problem, a transient analysis was performed for all connectors. It was found that transient voltage in the connector that failed most often was subjected to more high-frequency, high-amplitude AC components than the other three connectors. It was thought that these components caused partial discharge in the connector insulation and led to the insulation breakdown. Modification o...

  3. Four-quadrant flyback converter for direct audio power amplification

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    This paper presents a bidirectional, four-quadrant yback converter for use in direct audio power amplication. When compared to the standard Class-D switching-mode audio power amplier with separate power supply, the proposed four-quadrant flyback converter provides simple and compact solution with high efciency, higher level of integration, lower component count, less board space and eventually lower cost. Both peak and average current-mode control for use with 4Q flyback power converters are described and compared. Integrated magnetics is presented which simplies the construction of the auxiliary power supplies for control biasing and isolated gate drives. The feasibility of the approach is proven on audio power amplier prototype for subwoofer applications. (au)

  4. Very High Frequency Switch-Mode Power Supplies.:Miniaturization of Power Electronics.

    OpenAIRE

    Madsen, Mickey Pierre; Andersen, Michael A. E.; Knott, Arnold

    2015-01-01

    The importance of technology and electronics in our daily life is constantly increasing. At the same time portability and energy efficiency are currently some of the hottest topics. This creates a huge need for power converters in a compact form factor and with high efficiency, which can supply these electronic devices. This calls for new technologies in order to miniaturize the power electronics of today. One way to do this is by increasing the switching frequency dramatically and develop ve...

  5. Conducted EMI Mitigation Schemes in Isolated Switching-Mode Power Supply without the Need of a Y-capacitor

    DEFF Research Database (Denmark)

    Bai, Yongjiang; Yang, Xu; Zhang, Dan

    2017-01-01

    In order to construct a low impedance loop for common mode electromagnetic interference (EMI) signals, traditional method is to use Y-capacitors as filtering components. However, in the commonly used isolated AC-DC switching mode power supplies (SMPS), the Y-capacitors branch also behaves....... The goal of this paper is try to meet these two demands at the same time. In this paper, a novel non-Y-capacitor EMI design concept for SMPS is proposed for the first time. By getting rid of traditional EMI filtering component---the Y-capacitors, the leakage current can be eliminated entirely. Meanwhile......, to face with EMI design challenge, optimized transformer architecture is presented. Analysis of the transformer architecture as well as the auxiliary winding has been carried out. Then a novel topology suitable for non-Y-capacitors converter is proposed and the design procedure of the proposed topology...

  6. Insights into Dynamic Tuning of Magnetic-Resonant Wireless Power Transfer Receivers Based on Switch-Mode Gyrators

    Directory of Open Access Journals (Sweden)

    Mohamed Saad

    2018-02-01

    Full Text Available Magnetic-resonant wireless power transfer (WPT has become a reliable contactless source of power for a wide range of applications. WPT spans different power levels ranging from low-power implantable devices up to high-power electric vehicles (EV battery charging. The transmission range and efficiency of WPT have been reasonably enhanced by resonating the transmitter and receiver coils at a common frequency. Nevertheless, matching between resonance in the transmitter and receiver is quite cumbersome, particularly in single-transmitter multi-receiver systems. The resonance frequency in transmitter and receiver tank circuits has to be perfectly matched, otherwise power transfer capability is greatly degraded. This paper discusses the mistuning effect of parallel-compensated receivers, and thereof a novel dynamic frequency tuning method and related circuit topology and control is proposed and characterized in the system application. The proposed method is based on the concept of switch-mode gyrator emulating variable lossless inductors oriented to enable self-tunability in WPT receivers.

  7. A New Principle for a High Efficiency Power Audio Amplifier for Use with a Digital Preamplifier

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    1986-01-01

    The use of class-B and class-D amlifiers for converting digital audio signals to analog signals is discussed. It is shown that the class-D amplifier is unsuitable due to distortion. Therefore, a new principle involving a switch-mode power supply and a class-B amplifier is suggested. By regulating...... the supply voltage to the amplifier according to the amplitude of the audio signal, a higher efficiency than can be obtained by the current principles is achieved. The regulation can be done very efficiently by generating the control signal to the power supply in advance of the audio signal, made possible...

  8. Design of High-Voltage Switch-Mode Power Amplifier Based on Digital-Controlled Hybrid Multilevel Converter

    Directory of Open Access Journals (Sweden)

    Yanbin Hou

    2016-01-01

    Full Text Available Compared with conventional Class-A, Class-B, and Class-AB amplifiers, Class-D amplifier, also known as switching amplifier, employs pulse width modulation (PWM technology and solid-state switching devices, capable of achieving much higher efficiency. However, PWM-based switching amplifier is usually designed for low-voltage application, offering a maximum output voltage of several hundred Volts. Therefore, a step-up transformer is indispensably adopted in PWM-based Class-D amplifier to produce high-voltage output. In this paper, a switching amplifier without step-up transformer is developed based on digital pulse step modulation (PSM and hybrid multilevel converter. Under the control of input signal, cascaded power converters with separate DC sources operate in PSM switch mode to directly generate high-voltage and high-power output. The relevant topological structure, operating principle, and design scheme are introduced. Finally, a prototype system is built, which can provide power up to 1400 Watts and peak voltage up to ±1700 Volts. And the performance, including efficiency, linearity, and distortion, is evaluated by experimental tests.

  9. Tuning of Passivity-Preserving Controllers for Switched-Mode Power Converters

    NARCIS (Netherlands)

    Jeltsema, Dimitri; Scherpen, Jacquelien M.A.

    2004-01-01

    Nonlinear passivity-based control (PBC) algorithms for power converters have proved to be an interesting alternative to other, mostly linear, control techniques. The control objective is usually achieved through an energy reshaping process and by injecting damping to modify the dissipation structure

  10. Carrier Distortion in Hysteretic Self-Oscillating Class-D Audio Power

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Kofod; Andersen, Michael A. E.

    2009-01-01

    An important distortion mechanism in hysteretic self-oscillating (SO) class-D (switch mode) power amplifiers-–carrier distortion-–is analyzed and an optimization method is proposed. This mechanism is an issue in any power amplifier application where a high degree of proportionality between input...... proven in an audio power amplifier leading to THD figures that are comparable to the state of the art. Experimental hardware is a hysteretic SO bandpass current-mode-controlled single-ended audio power amplifier capable of 45 W into 8 Omega or 80 W into 4 Omega from a pm34 V supply with less than 0...

  11. High Efficiency, High Linearity, Switch Mode Power Amplifiers for Varying envelop Signal Applications

    DEFF Research Database (Denmark)

    Tong, Tian; Sira, Daniel; Nielsen, Michael

    2009-01-01

    Transmission of big h-order modulated signals at sufficient linearity while maintaining high power efficiency is always a challenge in modern communication application. Using conventional transmitter topologies, high linearity and high efficiency are two conflicting parameters somehow. However us...... width modulation technology and the outphasing configuration with SDR pre-distortion technology. The results presented show that all three solutions are capable of providing adequate performance....

  12. Bi-directional high-side current sense circuit for switch mode power supplies

    DEFF Research Database (Denmark)

    Ekhtiari, Marzieh; Bruun, Erik; Andersen, Michael A. E.

    2014-01-01

    In order to control a power supply using piezoelectric transformer, AC current in the transformer ne eds to be measured. Due to the control strategy it is necessary to measure amplitude, phase angle and zero crossing of this c urrent. In some applications there is common ground between pri mary...... and secondary sides of the transformer which is internally implemented inside the transformer. Therefore, curren t must be measured from the high voltage line in the presence of hig h input switching voltage. This paper proposes a resistive current s ensing circuit based on discrete components useful for input...... voltage s on the order of 200 V. The bandwidth is at least 200 kHz to allow fundamental frequency detection of piezoelectric transformers in use....

  13. Efficiency Investigation of Switch Mode Power Amplifier Drving Low Impedance Transducers

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Schneider, Henrik; Knott, Arnold

    2015-01-01

    The typical nominal resistance span of an electro dynamic transducer is 4 Ω to 8 Ω. This work examines the possibility of driving a transducer with a much lower impedance to enable the amplifier and loudspeaker to be directly driven by a low voltage source such as a battery. A method for estimating...... the amplifier rail voltage requirement as a function of the voice coil nominal resistance is presented. The method is based on a crest factor analysis of music signals and estimation of the electrical power requirement from a specific target of the sound pressure level. Experimental measurements confirms a huge...... performance leap in terms of efficiency compared to a conventional battery driven sound system. Future optimization of low voltage, high current amplifiers for low impedance loudspeaker drivers are discussed....

  14. Audio power amplifier design handbook

    CERN Document Server

    Self, Douglas

    2013-01-01

    This book is essential for audio power amplifier designers and engineers for one simple reason...it enables you as a professional to develop reliable, high-performance circuits. The Author Douglas Self covers the major issues of distortion and linearity, power supplies, overload, DC-protection and reactive loading. He also tackles unusual forms of compensation and distortion produced by capacitors and fuses. This completely updated fifth edition includes four NEW chapters including one on The XD Principle, invented by the author, and used by Cambridge Audio. Cro

  15. Efficient AlGaN/GaN Linear and Digital-Switch-Mode Power Amplifiers for Operation at 2GHz

    Science.gov (United States)

    Maroldt, Stephan; Wiegner, Dirk; Vitanov, Stanislav; Palankovski, Vassil; Quay, Rüdiger; Ambacher, Oliver

    This work addresses the enormous efficiency and linearity potential of optimized AlGaN/GaN high-electron mobility transistors (HEMT) in conventional Doherty linear base-station amplifiers at 2.7GHz. Supported by physical device simulation, the work further elaborates on the use of AlGaN/GaN HEMTs in high-speed current-switch-mode class-D (CMCD)/class-S MMICs for data rates of up to 8Gbit/s equivalent to 2GHz RF-operation. The device needs for switch-mode operation are derived and verified by MMIC results in class-S and class-D operation. To the authors' knowledge, this is the first time 2GHz-equivalent digital-switch-mode RF-operation is demonstrated with GaN HEMTs with high efficiency.

  16. Frequency dependent loss analysis and minimization of system losses in switchmode audio power amplifiers

    DEFF Research Database (Denmark)

    Yamauchi, Akira; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2014-01-01

    In this paper, frequency dependent losses in switch-mode audio power amplifiers are analyzed and a loss model is improved by taking the voltage dependence of the parasitic capacitance of MOSFETs into account. The estimated power losses are compared to the measurement and great accuracy is achieved....... By choosing the optimal switching frequency based on the proposed analysis, the experimental results show that system power losses of the reference design are minimized and an efficiency improvement of 8 % in maximum is achieved without compromising audio performances....

  17. Improvement of out-of-band Behaviour in Switch-Mode Amplifiers and Power Supplies by their Modulation Topology

    DEFF Research Database (Denmark)

    Knott, Arnold

    2010-01-01

    will be put into perspective and self-oscillating amplifiers will be compared with external synchronized topologies. After that, solutions to the problem, which are widespread in industry will be given and explained (chapter 3). The challenges and advantages will be described. The improvement of the described...... the interference of power electronics circuits and telecommunication circuits is to stay away from the frequencies used for information transmission. Even though the electromagnetic spectrum is used without any exceptions, the situation can be optimized for audio applications. This is done by using switching...

  18. A new principle for a high-efficiency power audio amplifier for use with a digital preamplifier

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    1987-01-01

    The use of class-B and class-D amplifiers for converting digital audio signals to analog signals is discussed. It is shown that the class-D amplifier is unsuitable due to distortion. Therefore a new principle involving a switch-mode power supply and a class-B amplifier is suggested. By regulating...... the supply voltage to the amplifier according to the amplitude of the audio signal, a higher efficiency than can be obtained by the usual principles is achieved. The regulation can be done very efficiently by generating the control signal to the power supply in advance of the audio signal, made possible...

  19. A New Principle for a High Efficiency Power Audio Amplifier for Use with a Digital Preamplifier

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    1986-01-01

    The use of class-B and class-D amlifiers for converting digital audio signals to analog signals is discussed. It is shown that the class-D amplifier is unsuitable due to distortion. Therefore, a new principle involving a switch-mode power supply and a class-B amplifier is suggested. By regulating...... the supply voltage to the amplifier according to the amplitude of the audio signal, a higher efficiency than can be obtained by the current principles is achieved. The regulation can be done very efficiently by generating the control signal to the power supply in advance of the audio signal, made possible...... by the digital signal from the preamplifier. A prototype shows possibilities for further developments....

  20. Low Power Very High Frequency Switch-Mode Power Supply with 50 V Input and 5 V Output

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the design of a resonant converter with a switching frequency in the very high frequencyrange (30-300 MHz), a large step down ratio (10 times) and low output power (1 W). Several different invertersand rectifiers are analyzed and compared. The class E inverter and rectifier ar...

  1. Application of small-signal modeling and measurement techniques to the stability analysis of an integrated switching-mode power system. [onboard Dynamics Explorer Satellite

    Science.gov (United States)

    Wong, R. C.; Owen, H. A., Jr.; Wilson, T. G.; Rodriguez, G. E.

    1980-01-01

    Small-signal modeling techniques are used in a system stability analysis of a breadboard version of a complete functional electrical power system. The system consists of a regulated switching dc-to-dc converter, a solar-cell-array simulator, a solar-array EMI filter, battery chargers and linear shunt regulators. Loss mechanisms in the converter power stage, including switching-time effects in the semiconductor elements, are incorporated into the modeling procedure to provide an accurate representation of the system without requiring frequency-domain measurements to determine the damping factor. The small-signal system model is validated by the use of special measurement techniques which are adapted to the poor signal-to-noise ratio encountered in switching-mode systems. The complete electrical power system with the solar-array EMI filter is shown to be stable over the intended range of operation.

  2. Estimation of Parasitic Resistance of Electrolytic Capacitor and Filter Inductor and Prediction of Input Filter Induced Oscillations in a Switch-Mode Magnet Power Supply

    Directory of Open Access Journals (Sweden)

    Rajul Lal Gour

    2016-01-01

    Full Text Available In switch-mode power converters with large ratings, it is important to be able to predict the parasitic resistances associated with circuit elements such as electrolytic capacitor and filter inductor in the initial converter design stage itself to avoid the cost and time associated with actual design, prototype fabrication, and testing of these components. Knowing the values of parasitic elements is also important as they decide the possibility of closed-loop instability, besides affecting the other circuit parameters. In this paper, a way to estimate the equivalent series resistance of electrolytic capacitor and the winding resistance of filter inductor is proposed leading to their closed form expressions in terms of system parameters. Using these, procedure to predict the closed-loop instability induced due to the input filter is exemplified with illustrative calculations.

  3. Performance Analysis of Multiradio Transmitter with Polar or Cartesian Architectures Associated with High Efficiency Switched-Mode Power Amplifiers (invited paper

    Directory of Open Access Journals (Sweden)

    F. Robert

    2010-12-01

    Full Text Available This paper deals with wireless multi-radio transmitter architectures operating in the frequency band of 800 MHz – 6 GHz. As a consequence of the constant evolution in the communication systems, mobile transmitters must be able to operate at different frequency bands and modes according to existing standards specifications. The concept of a unique multiradio architecture is an evolution of the multistandard transceiver characterized by a parallelization of circuits for each standard. Multi-radio concept optimizes surface and power consumption. Transmitter architectures using sampling techniques and baseband ΣΔ or PWM coding of signals before their amplification appear as good candidates for multiradio transmitters for several reasons. They allow using high efficiency power amplifiers such as switched-mode PAs. They are highly flexible and easy to integrate because of their digital nature. But when the transmitter efficiency is considered, many elements have to be taken into account: signal coding efficiency, PA efficiency, RF filter. This paper investigates the interest of these architectures for a multiradio transmitter able to support existing wireless communications standards between 800 MHz and 6 GHz. It evaluates and compares the different possible architectures for WiMAX and LTE standards in terms of signal quality and transmitter power efficiency.

  4. Frequency Compensation of an Audio Power Amplifier

    NARCIS (Netherlands)

    van der Zee, Ronan A.R.; van Heeswijk, R.

    2006-01-01

    A car audio power amplifier is presented that uses a frequency compensation scheme which avoids large compensation capacitors around the MOS power transistors, while retaining the bandwidth and stable load range of nested miller compensation. THD is 0.005%@(1kHz, 10W), SNR is 108dB, and the

  5. A new principle for a high-efficiency power audio amplifier for use with a digital preamplifier

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    1987-01-01

    The use of class-B and class-D amplifiers for converting digital audio signals to analog signals is discussed. It is shown that the class-D amplifier is unsuitable due to distortion. Therefore a new principle involving a switch-mode power supply and a class-B amplifier is suggested. By regulating...... the supply voltage to the amplifier according to the amplitude of the audio signal, a higher efficiency than can be obtained by the usual principles is achieved. The regulation can be done very efficiently by generating the control signal to the power supply in advance of the audio signal, made possible...... by a preceding digital signal from the preamplifier. A prototype shows possibilities for further developments...

  6. Switched-mode converters (one quadrant)

    CERN Document Server

    Barrade, P

    2006-01-01

    Switched-mode converters are DC/DC converters that supply DC loads with a regulated output voltage, and protection against overcurrents and short circuits. These converters are generally fed from an AC network via a transformer and a conventional diode rectifier. Switched-mode converters (one quadrant) are non-reversible converters that allow the feeding of a DC load with unipolar voltage and current. The switched-mode converters presented in this contribution are classified into two families. The first is dedicated to the basic topologies of DC/DC converters, generally used for low- to mid-power applications. As such structures enable only hard commutation processes, the main drawback of such topologies is high commutation losses. A typical multichannel evolution is presented that allows an interesting decrease in these losses. Deduced from this direct DC/DC converter, an evolution is also presented that allows the integration of a transformer into the buck and the buck–boost structure. This enables an int...

  7. Switched Mode Four-Quadrant Converters

    CERN Document Server

    Thurel, Y

    2015-01-01

    This paper was originally presented at CAS-2004, and was slightly modified for CAS-2014. It presents a review of the key parameters that impact the design choices for a true four-quadrant power converter, in the range 1-10 kW, mainly based on switching mode converter topology. This paper will first describe the state-of-the-art for this power converter family, giving the drawbacks and advantages of different possible solutions. It will also present practical results obtained from the CERN-designed converter. It will finally give some important tips regarding critical phases like test one, when conducting a project dealing with this type of power converter.

  8. Debugging of Class-D Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Crone, Lasse; Pedersen, Jeppe Arnsdorf; Mønster, Jakob Døllner

    2012-01-01

    Determining and optimizing the performance of a Class-D audio power amplier can be very dicult without knowledge of the use of audio performance measuring equipment and of how the various noise and distortion sources in uence the audio performance. This paper gives an introduction on how to measure...

  9. Four-quadrant flyback converter for direct audio power amplification

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a bidirectional, four-quadrant flyback converter for use in direct audio power amplification. When compared to the standard Class-D switching audio power amplifier with a separate power supply, the proposed four-quadrant flyback converter provides simple solution with better...

  10. Debugging of Class-D Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Crone, Lasse; Pedersen, Jeppe Arnsdorf; Mønster, Jakob Døllner

    2012-01-01

    Determining and optimizing the performance of a Class-D audio power amplier can be very dicult without knowledge of the use of audio performance measuring equipment and of how the various noise and distortion sources in uence the audio performance. This paper gives an introduction on how to measure...... the performance of the amplier and how to nd the noise and distortion sources and suggests ways to remove them. Throughout the paper measurements of a test amplier are presented along with the relevant theory....

  11. Commissioning and operation of 130 kV/130 A switched-mode HV power supplies with the upgraded JET neutral beam injectors

    International Nuclear Information System (INIS)

    Edwards, D.C.; Bigi, M.; Brown, D.P.D.; Ganuza, D.; Garcia, F.; Hudson, Z.; Jones, T.T.C.; Perez, A.

    2005-01-01

    The design features, on-site testing, commissioning and operation are described of two new 130 kV/130 A HV power supply units serving four upgraded 130 kV/60 A positive ion neutral injectors (PINIs) on JET. Both units were factory tested at full power and pulse length into dummy resistive load. Following on-site installation, the factory tests were repeated. The transition from dummy-load testing to PINI operation required full integration of the HVPS within the overall JET control system, and rigorous testing of the co-ordinated actions and protections of all PINI power supplies (filament and arc for plasma source and negative suppression grid). The implementation of these functions is described. Extensive use was made of parasitic integrated test pulses, where the other PINIs could be operated normally, with the HVPS energised under full remote control together with the corresponding PINI plasma sources, but with the HVPS connected to dummy load. The amount of NB operation time dedicated to commissioning was thereby minimised, yet gave a high degree of confidence of readiness for HV energisation of the PINI, and first beam operation followed less than 24 h from HV connection to the PINI. The routine operating experience and performance, including load protection characteristics of the new HVPS units are also described

  12. A Power Efficient Audio Amplifier Combining Switching and Linear Techniques

    NARCIS (Netherlands)

    van der Zee, Ronan A.R.; van Tuijl, Adrianus Johannes Maria

    1998-01-01

    Integrated Class D audio amplifiers are very power efficient, but require an external filter which prevents further integration. Also due to this filter, large feedback factors are hard to realise, so that the load influences the distortion- and transfer characteristics. The amplifier presented in

  13. Energy harvesting from an exercise bike using a switch-mode converter controlled generator

    DEFF Research Database (Denmark)

    Knott, Arnold; Lindberg-Poulsen, Kristian; Andersen, Thomas

    2010-01-01

    This paper investigates the feasibility of using an alternator as means of harvesting energy from a stationary exercise bicycle. A switch mode converter was designed to regulate the current in the alternator rotor winding, thus regulating the power required to pedal, and consequently the power...

  14. Design And Construction Of 300W Audio Power Amplifier For Classroom

    Directory of Open Access Journals (Sweden)

    Shune Lei Aung

    2015-07-01

    Full Text Available Abstract This paper describes the design and construction of 300W audio power amplifier for classroom. In the construction of this amplifier microphone preamplifier tone preamplifier equalizer line amplifier output power amplifier and sound level indicator are included. The output power amplifier is designed as O.C.L system and constructed by using Class B among many types of amplifier classes. There are two types in O.C.L system quasi system and complementary system. Between them the complementary system is used in the construction of 300W audio power amplifier. The Multisim software is utilized for the construction of audio power amplifier.

  15. System Level Power Optimization of Digital Audio Back End for Hearing Aids

    DEFF Research Database (Denmark)

    Pracny, Peter; Jørgensen, Ivan Harald Holger; Bruun, Erik

    2017-01-01

    This work deals with power optimization of the audio processing back end for hearing aids - the interpolation filter (IF), the sigma-delta (SD modulator and the Class D power amplifier (PA) as a whole. Specifications are derived and insight into the tradeoffs involved is used to optimize the inte......This work deals with power optimization of the audio processing back end for hearing aids - the interpolation filter (IF), the sigma-delta (SD modulator and the Class D power amplifier (PA) as a whole. Specifications are derived and insight into the tradeoffs involved is used to optimize...... to track the hardware and power demands as the tradeoffs of the system level parameters are investigated. The result is the digital part of the back end optimized with respect to power which provides audio performance comparable to state-of-theart. A combination of system level parameters leading...

  16. Output Impedance Shaping for Frequency Compensation of MOS Audio Power Amplifiers

    NARCIS (Netherlands)

    van der Zee, Ronan A.R.; Mostert, Fred

    2009-01-01

    A frequency compensation technique for MOS audio power amplifiers is presented that allows the frequency compensation capacitors around the power transistors to be smaller than the circuit parasitics without power or stability penalty. Stability is analysed by inspecting the output impedance of the

  17. A high efficiency PWM CMOS class-D audio power amplifier

    Science.gov (United States)

    Zhangming, Zhu; Lianxi, Liu; Yintang, Yang; Han, Lei

    2009-02-01

    Based on the difference close-loop feedback technique and the difference pre-amp, a high efficiency PWM CMOS class-D audio power amplifier is proposed. A rail-to-rail PWM comparator with window function has been embedded in the class-D audio power amplifier. Design results based on the CSMC 0.5 μm CMOS process show that the max efficiency is 90%, the PSRR is -75 dB, the power supply voltage range is 2.5-5.5 V, the THD+N in 1 kHz input frequency is less than 0.20%, the quiescent current in no load is 2.8 mA, and the shutdown current is 0.5 μA. The active area of the class-D audio power amplifier is about 1.47 × 1.52 mm2. With the good performance, the class-D audio power amplifier can be applied to several audio power systems.

  18. A High-Efficiency 4x45W Car Audio Power Amplifier using Load Current Sharing

    NARCIS (Netherlands)

    Mensink, C.H.J.; Mensink, C.; van Tuijl, Adrianus Johannes Maria; Gierkink, Sander L.J.; Mostert, F.; van der Zee, Ronan A.R.

    2010-01-01

    A 4x45W (EIAJ) monolithic car audio power amplifier is presented that achieves a power dissipation decrease of nearly 2x over standard class AB operation by sharing load currents between loudspeakers. Output signals are conditioned using a common-mode control loop to allow switch placement between

  19. A power supply error correction method for single-ended digital audio class D amplifiers

    Science.gov (United States)

    Yu, Zeqi; Wang, Fengqin; Fan, Yangyu

    2016-12-01

    In single-ended digital audio class D amplifiers (CDAs), the errors caused by power supply noise in the power stages degrade the output performance seriously. In this article, a novel power supply error correction method is proposed. This method introduces the power supply noise of the power stage into the digital signal processing block and builds a power supply error corrector between the interpolation filter and the uniform-sampling pulse width modulation (UPWM) lineariser to pre-correct the power supply error in the single-ended digital audio CDA. The theoretical analysis and implementation of the method are also presented. To verify the effectiveness of the method, a two-channel single-ended digital audio CDA with different power supply error correction methods is designed, simulated, implemented and tested. The simulation and test results obtained show that the method can greatly reduce the error caused by the power supply noise with low hardware cost, and that the CDA with the proposed method can achieve a total harmonic distortion + noise (THD + N) of 0.058% for a -3 dBFS, 1 kHz input when a 55 V linear unregulated direct current (DC) power supply (with the -51 dBFS, 100 Hz power supply noise) is used in the power stages.

  20. Power Parameters and Efficiency of Class B Audio Amplifiers in Real-World Scenario

    Directory of Open Access Journals (Sweden)

    H. Zhivomirov

    2017-04-01

    Full Text Available Consumer audio amplifiers are intended to op¬erate with various loudspeaker loads, i.e. the load imped¬ance profile of the audio amplifier is a priori unknown. We propose the power parameters analysis of the class B audio amplifiers to be carried out in the realistic worst-case (RWC scenario of operation with the minimal value of the impedance and a RWC type of signal, instead of the nominal impedance of the loudspeaker and a sine-wave signal. Experimental validation, carried out for different types of signals and loudspeaker loads, demonstrate the advantages of the proposed RWC-based power parameters estimation. Furthermore, we provide a way of assessing the safe-operating area (SOA boundaries, based on the output I-V loci of the amplifier and by means of an equi¬valent load line (ELL.

  1. Design And Construction Of 300W Audio Power Amplifier For Classroom

    OpenAIRE

    Shune Lei Aung; Kyaw Soe Lwin and Hla Myo Tun

    2015-01-01

    Abstract This paper describes the design and construction of 300W audio power amplifier for classroom. In the construction of this amplifier microphone preamplifier tone preamplifier equalizer line amplifier output power amplifier and sound level indicator are included. The output power amplifier is designed as O.C.L system and constructed by using Class B among many types of amplifier classes. There are two types in O.C.L system quasi system and complementary system. Between them the comple...

  2. A power-efficient audio amplifier combining switching and linear techniques

    NARCIS (Netherlands)

    van der Zee, Ronan A.R.; van Tuijl, Adrianus Johannes Maria

    1999-01-01

    Integrated class-D audio amplifiers are very power efficient but require an external LC reconstruction filter, which prevents further integration. Also due to this filter, large feedback factors are hard to realize, so that the load influences the distortion and transfer characteristics. The 30 W

  3. An audio FIR-DAC in a BCD process for high power Class-D amplifiers

    NARCIS (Netherlands)

    Doorn, T.S.; van Tuijl, Adrianus Johannes Maria; Schinkel, Daniel; Annema, Anne J.; Berkhout, M.; Berkhout, M.; Nauta, Bram

    A 322 coefficient semi-digital FIR-DAC using a 1-bit PWM input signal was designed and implemented in a high voltage, audio power bipolar CMOS DMOS (BCD) process. This facilitates digital input signals for an analog class-D amplifier in BCD. The FIR-DAC performance depends on the ISI-resistant

  4. Cr:ZnS saturable absorber passively Q-switched mode-locking Tm,Ho:LLF laser.

    Science.gov (United States)

    Zhang, Xinlu; Luo, Yong; Wang, Tianhan; Dai, Junfeng; Zhang, Jianxin; Li, Jiang; Cui, Jinhui; Huang, Jinjer

    2017-04-10

    We first report on a diode-end-pumped passively Q-switched mode-locking Tm,Ho:LLF laser at 2053 nm by using a Cr:ZnS saturable absorber. A stable Q-switched mode-locking pulse train with a nearly 100% modulation depth was achieved. The repetition frequency of the Q-switched pulse envelope increased from 0.5 to 12.3 kHz with increasing pump power from 1 to 4.36 W. The maximum average output power of 145 mW was obtained, and the width of the mode-locked pulse was estimated to be less than 682 ps with a 250 MHz repetition frequency within a Q-switched pulse envelope of about 700 ns.

  5. A dual mode charge pump with adaptive output used in a class G audio power amplifier

    Science.gov (United States)

    Yong, Feng; Zhenfei, Peng; Shanshan, Yang; Zhiliang, Hong; Yang, Liu

    2011-04-01

    A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented. According to the amplitude of the input signals, the charge pump has two level output voltage rails available to save power. It operates both in current mode at high output load and in pulse frequency modulation (PFM) at light load to reduce the power dissipation. Also, dynamic adjustment of the power stage transistor size based on load current at the PFM mode is introduced to reduce the output voltage ripple and prevent the switching frequency from audio range. The prototype is implemented in 0.18 μm 3.3 V CMOS technology. Experimental results show that the maximum power efficiency of the charge pump is 79.5% @ 0.5x mode and 83.6% @ 1x mode. The output voltage ripple is less than 15 mV while providing 120 mA of the load current at PFM control and less than 18 mV while providing 300 mA of the load current at current mode control. An analytical model for ripple voltage and efficiency calculation of the proposed PFM control demonstrates reasonable agreement with measured results.

  6. Design of low power and low area passive sigma delta modulators for audio applications

    CERN Document Server

    Fouto, David

    2017-01-01

    This book presents the study, design, modulation, optimization and implementation of low power, passive DT-ΣΔMs for use in audio applications. The high gain and bandwidth amplifier normally used for integration in ΣΔ modulation, is replaced by passive, switched-capacitor branches working under the Ultra Incomplete Settling (UIS) condition, leading to a reduction of the consumed power. The authors describe a design process that uses high level models and an optimization process based in genetic algorithms to achieve the desired performance.

  7. Audio-frequency noise emissions from high-voltage overhead power lines; Tonale Schallemissionen von Hochspannungsfreileitungen

    Energy Technology Data Exchange (ETDEWEB)

    Semmler, M.; Straumann, U.; Roero, C.; Teich, T. H.

    2005-07-01

    This article discusses the noise-emissions caused by high-voltage overhead power lines that can occur under certain atmospheric conditions. These emissions, caused by electric discharges around the conductors, can achieve disturbing values, depending on the conditions prevailing at the time in question. The causes of the discharges are examined and the ionisation processes involved are looked at. The parameters influencing the discharges are discussed and measures that can be taken to reduce such audio-frequency emissions are looked at. The authors note that a reduction of peripheral field strengths can reduce emissions and that hydrophilic coatings can lead to faster reduction of such effects after rainfall.

  8. Audio-frequency noise emissions from high-voltage overhead power lines

    International Nuclear Information System (INIS)

    Semmler, M.; Straumann, U.; Roero, C.; Teich, T. H.

    2005-01-01

    This article discusses the noise-emissions caused by high-voltage overhead power lines that can occur under certain atmospheric conditions. These emissions, caused by electric discharges around the conductors, can achieve disturbing values, depending on the conditions prevailing at the time in question. The causes of the discharges are examined and the ionisation processes involved are looked at. The parameters influencing the discharges are discussed and measures that can be taken to reduce such audio-frequency emissions are looked at. The authors note that a reduction of peripheral field strengths can reduce emissions and that hydrophilic coatings can lead to faster reduction of such effects after rainfall

  9. High-performance combination method of electric network frequency and phase for audio forgery detection in battery-powered devices.

    Science.gov (United States)

    Savari, Maryam; Abdul Wahab, Ainuddin Wahid; Anuar, Nor Badrul

    2016-09-01

    Audio forgery is any act of tampering, illegal copy and fake quality in the audio in a criminal way. In the last decade, there has been increasing attention to the audio forgery detection due to a significant increase in the number of forge in different type of audio. There are a number of methods for forgery detection, which electric network frequency (ENF) is one of the powerful methods in this area for forgery detection in terms of accuracy. In spite of suitable accuracy of ENF in a majority of plug-in powered devices, the weak accuracy of ENF in audio forgery detection for battery-powered devices, especially in laptop and mobile phone, can be consider as one of the main obstacles of the ENF. To solve the ENF problem in terms of accuracy in battery-powered devices, a combination method of ENF and phase feature is proposed. From experiment conducted, ENF alone give 50% and 60% accuracy for forgery detection in mobile phone and laptop respectively, while the proposed method shows 88% and 92% accuracy respectively, for forgery detection in battery-powered devices. The results lead to higher accuracy for forgery detection with the combination of ENF and phase feature. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. High efficiency class-I audio power amplifier using a single adaptive supply

    Science.gov (United States)

    Zhenfei, Peng; Shanshand, Yang; Yong, Feng; Yang, Liu; Zhiliang, Hong

    2012-09-01

    A high efficiency class-I linear audio power amplifier (PA) with an adaptive supply is presented. Its efficiency is improved by a dynamic supply to reduce the power transistors' voltage drop. A gain compression technique is adopted to make the amplifier accommodate a single positive supply. Circuit complicity and chip area are reduced because no charge pump is necessary for the negative supply. A common shared mode voltage and a symmetric layout pattern are used to minimize the non-linearity. A peak efficiency of 80% is reached at peak output power. The measured THD+N before and after the supply switching point are 0.01% and 0.05%, respectively. The maximum output power is 410 mW for an 8 Ω speaker load. Unlike switching amplifiers, the class-I amplifier operates as a linear amplifier and hence has a low EMI. The advantage of a high efficiency and low EMI makes the class-I amplifier suitable for portable and RF sensitive applications.

  11. Safe-commutation principle for direct single-phase AC-AC converters for use in audio power amplification

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2004-01-01

    This paper presents an alternative safe commutation principle for a single phase bidirectional bridge, for use in the new generation of direct single-stage AC-AC audio power amplifiers. As compared with the bridge commutation with load current or source voltage sensing, in this approach...

  12. EXPERIMENTAL STUDIES FOR DEVELOPMENT HIGH-POWER AUDIO SPEAKER DEVICES PERFORMANCE USING PERMANENT NdFeB MAGNETS SPECIAL TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Constantin D. STĂNESCU

    2013-05-01

    Full Text Available In this paper the authors shows the research made for improving high-power audio speaker devices performance using permanent NdFeB magnets special technology. Magnetic losses inside these audio devices are due to mechanical system frictions and to thermal effect of Joules eddy currents. In this regard, by special technology, were made conical surfaces at top plate and center pin. Analysing results obtained by modelling the magnetic circuit finite element method using electronic software package,was measured increase efficiency by over 10 %, from 1,136T to13T.

  13. SEMICONDUCTOR INTEGRATED CIRCUITS: A high-performance, low-power σ Δ ADC for digital audio applications

    Science.gov (United States)

    Hao, Luo; Yan, Han; Cheung, Ray C. C.; Xiaoxia, Han; Shaoyu, Ma; Peng, Ying; Dazhong, Zhu

    2010-05-01

    A high-performance low-power σ Δ analog-to-digital converter (ADC) for digital audio applications is described. It consists of a 2-1 cascaded σ Δ modulator and a decimation filter. Various design optimizations are implemented in the system design, circuit implementation and layout design, including a high-overload-level coefficient-optimized modulator architecture, a power-efficient class A/AB operational transconductance amplifier, as well as a multi-stage decimation filter conserving area and power consumption. The ADC is implemented in the SMIC 0.18-μm CMOS mixed-signal process. The experimental chip achieves a peak signal-to-noise-plus-distortion ratio of 90 dB and a dynamic range of 94 dB over 22.05-kHz audio band and occupies 2.1 mm2, which dissipates only 2.1 mA quiescent current in the analog circuits.

  14. Investigation of Energy Consumption and Sound Quality for Class-D Audio Amplifiers using Tracking Power Supplies

    DEFF Research Database (Denmark)

    Yamauchi, Akira; Schneider, Henrik; Knott, Arnold

    2015-01-01

    and a concern in other applications where multiple amplifier channels are generating heat problems. It is found that power losses at low power levels account for close to 78 % of the energy consumption based on typical consumer behavior investigations. This paper investigates the theoretical limits of stepless...... power supply tracking and its influence on power losses, audio performance and environmental impact for a 130 W class-D amplifier prototype as well as a commercialized class-D amplifier. Both modeled and experimental results verify that a large improvement of efficiency can be achieved. The total...

  15. Audio power amplifier techniques with energy efficient power conversion. Vol. 1

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Karsten

    1998-04-01

    A fundamental study of both analog and digital pulse modulation methods is carried out. A novel class of multi-level pulse modulation methods - Phase Shifted Carrier Pulse Width Modulation (PSCPWM) - is introduced and show to have several advantageous features, primarily caused by the much improved synthesis of the modulating signal. Enhanced digital pulse modulation methods for digital Pulse Modulation Amplifier (PMA) systems are investigated, and a simple methodology for digital PWM modulator synthesis is devised. It is concluded, that the modulator performance is not a limitation in the system, regardless of the domain of modulator implementation. Power conversion in PMA systems is adressed from the perspective of both linearity and efficienty optimization. Based on detailed studies of the distortion mechanisms in the power conversion stage it is concluded, that this is the fundamental limitation on system performance due to several physical limitations. The analysis of general power stage efficiency concludes that dramatic improvements in energy efficiency are possible with PMA systems that are optimized for efficiency. A control system design methodology is devised as a platform for synthesis of robust control systems. Investigations of three fundamental control structures show that even simple control systems offer a remarkable value, although the considered topologies also have their limitations which is verified by practical evaluation in hardware. A novel control method is introduced - Multivariable Enhanced Cascade Control (MECC). MECC provides flexible control over all essential system parameters and is furthermore simple in realization. Practical evaluation of a MECC based PMA shows state-of-the-art performance. The application of non-linear control methods is investigated with the introduction of an enhanced non-linear control/modulator topology. Although the non-linear controller is theoretically interesting, the method proves to suffer from various

  16. High frequency switched-mode stimulation can evoke postsynaptic responses in cerebellar principal neurons

    Directory of Open Access Journals (Sweden)

    Marijn Van Dongen

    2015-03-01

    Full Text Available This paper investigates the efficacy of high frequency switched-mode neural stimulation. Instead of using a constant stimulation amplitude, the stimulus is switched on and off repeatedly with a high frequency (up to 100kHz duty cycled signal. By means of tissue modeling that includes the dynamic properties of both the tissue material as well as the axon membrane, it is first shown that switched-mode stimulation depolarizes the cell membrane in a similar way as classical constant amplitude stimulation.These findings are subsequently verified using in vitro experiments in which the response of a Purkinje cell is measured due to a stimulation signal in the molecular layer of the cerebellum of a mouse. For this purpose a stimulator circuit is developed that is able to produce a monophasic high frequency switched-mode stimulation signal. The results confirm the modeling by showing that switched-mode stimulation is able to induce similar responses in the Purkinje cell as classical stimulation using a constant current source. This conclusion opens up possibilities for novel stimulation designs that can improve the performance of the stimulator circuitry. Care has to be taken to avoid losses in the system due to the higher operating frequency.

  17. Safe-commutation principle for direct single-phase AC-AC converters for use in audio power amplification

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    This paper presents an alternative safe commutation principle for a single phase bidirectional bridge, for use in the new generation of direct single-stage AC-AC audio power amplifiers. As compared with the bridge commutation with load current or source voltage sensing, in this approach it is not required to do any measurements, thus making it more reliable. Initial testing made on the prototype prove the feasibility of the approach. (au)

  18. Audio Papers

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh; Samson, Kristine

    2016-01-01

    With this special issue of Seismograf we are happy to present a new format of articles: Audio Papers. Audio papers resemble the regular essay or the academic text in that they deal with a certain topic of interest, but presented in the form of an audio production. The audio paper is an extension...

  19. All Digital Switch-Mode DC/DC Converters with BIST Functionality for Harsh Space Environments, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Space Micro Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...

  20. AIR ATMOSPHERIC-PRESSURE DISCHARGERS FOR OPERATION IN HIGH-FREQUENCY SWITCHING MODE.

    Directory of Open Access Journals (Sweden)

    L.S. Yevdoshenko

    2013-10-01

    Full Text Available Operation of two designs of compact multigap dischargers has been investigated in a high-frequency switching mode. It is experimentally revealed that the rational length of single discharge gaps in the designs is 0.3 mm, and the maximum switching frequency is 27000 discharges per second under long-term stable operation of the dischargers. It is shown that in pulsed corona discharge reactors, the pulse front sharpening results in increasing the operating electric field strength by 1.3 – 1.8 times.

  1. Mixed-Signal Architectures for High-Efficiency and Low-Distortion Digital Audio Processing and Power Amplification

    Directory of Open Access Journals (Sweden)

    Pierangelo Terreni

    2010-01-01

    Full Text Available The paper addresses the algorithmic and architectural design of digital input power audio amplifiers. A modelling platform, based on a meet-in-the-middle approach between top-down and bottom-up design strategies, allows a fast but still accurate exploration of the mixed-signal design space. Different amplifier architectures are configured and compared to find optimal trade-offs among different cost-functions: low distortion, high efficiency, low circuit complexity and low sensitivity to parameter changes. A novel amplifier architecture is derived; its prototype implements digital processing IP macrocells (oversampler, interpolating filter, PWM cross-point deriver, noise shaper, multilevel PWM modulator, dead time compensator on a single low-complexity FPGA while off-chip components are used only for the power output stage (LC filter and power MOS bridge; no heatsink is required. The resulting digital input amplifier features a power efficiency higher than 90% and a total harmonic distortion down to 0.13% at power levels of tens of Watts. Discussions towards the full-silicon integration of the mixed-signal amplifier in embedded devices, using BCD technology and targeting power levels of few Watts, are also reported.

  2. Audio Twister

    DEFF Research Database (Denmark)

    Cermak, Daniel; Moreno Garcia, Rodrigo; Monastiridis, Stefanos

    2015-01-01

    Daniel Cermak-Sassenrath, Rodrigo Moreno Garcia, Stefanos Monastiridis. Audio Twister. Installation. P-Hack Copenhagen 2015, Copenhagen, DK, Apr 24, 2015.......Daniel Cermak-Sassenrath, Rodrigo Moreno Garcia, Stefanos Monastiridis. Audio Twister. Installation. P-Hack Copenhagen 2015, Copenhagen, DK, Apr 24, 2015....

  3. Standby power consumption in U.S. residences

    Energy Technology Data Exchange (ETDEWEB)

    Huber, W.

    1997-12-01

    {open_quotes}Leaking electricity{close_quotes} is the electricity consumed by appliances while they are switched {open_quotes}off{close_quote} or not performing their principal function. Leaking electricity represents approximately 5 % of U.S. residential electricity. This is a relatively new phenomenon and is a result of proliferation of electronic equipment in homes. The standby losses in TVs, VCRs, compact audio systems, and cable boxes account for almost 40% of all leaking electricity. There is a wide range in standby losses in each appliance group. For example, standby losses in compact audio systems range from 2.1 to 28.6 W, even though their features are identical. In some cases, leaking electricity while switched off was only slightly less than energy consumption in the on mode. New features in these appliances may greatly increase leaking electricity, such as electronic program guides in TVs and cable boxes. In the standby mode, these new features require many extra components energized to permit the downloading of information. Several techniques are available to cut standby losses, most without using any new technologies. Simple redesign of circuits to avoid energizing unused components appears to save the most energy. A separate power supply, precisely designed for the actual power needed, is another solution. A switch mode power supply can substitute for the less efficient linear power supply. Switch mode power supplies cut no-load and standby losses by 60-80%. The combination of these techniques can cut leaking electricity by greater than 75%.

  4. Audio Fingerprint Untuk Identifikasi File Audio

    OpenAIRE

    Yuanto, Stefanus Irwan; Tampubolon, Junius Karel; Restyandito, Restyandito

    2007-01-01

    Identifikasi file audio secara biner kurang efektif karena adanya format penyimpanan dan cara penyimpanan file audio yang berbeda-beda. Dengan menerapkan konsep audio fingerprint maka sinyal audio akan diidentifikasi dengan membandingkan sebuah kode unik berukuran kecil yang mewakili sinyal audio tersebut sehingga perbedaan format dan cara penyimpanan tidak berpengaruh besar terhadap sebuah proses identifikasi audio.

  5. Derivation and Analysis of a Low-Cost, High-performance Analogue BPCM Control Scheme for Class-D Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael A. E.

    2005-01-01

    This paper presents a low-cost analogue control scheme for class-D audio power amplifiers. The scheme is based around bandpass current-mode (BPCM) control, and provides ample stability margins and low distortion over a wide range of operating conditions. Implementation is very simple and does...

  6. Effect of voltage sags on digitally controlled line connected switched-mode power supplies

    DEFF Research Database (Denmark)

    Török, Lajos; Munk-Nielsen, Stig

    2012-01-01

    immunity to these voltage deviations. In the following paper an analysis of different grid disturbances is presented. Some limitations and immunity requirements based on standards for devices connected to low voltage grid are described. The behavior of digitally controlled boost PFC converter in case...

  7. Printed Circuit Board Embedded Inductors for Very High Frequency Switch-Mode Power Supplies

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    The paper describes the design of three different structures for printed circuit board embedded inductors. Direct comparison of spirals, solenoids and toroids are made with regard to inductance, dc and ac resistance, electromagnetic field and design flexibility. First the equations for the impeda......The paper describes the design of three different structures for printed circuit board embedded inductors. Direct comparison of spirals, solenoids and toroids are made with regard to inductance, dc and ac resistance, electromagnetic field and design flexibility. First the equations...... to take possible electromagnetic interference problems into account, when the structures are compared. The simulated fields are verified through near field measurements performed on the prototypes. Finally design flexibility are considered, both regarding scalability and design of the individual inductors...

  8. Self-organization of the Q-switched mode-locked regime in a diode-pumped Nd:YAG laser

    Science.gov (United States)

    Donin, V. I.; Yakovin, D. V.; Gribanov, A. V.

    2015-06-01

    A new Q-switched mode-locked generation regime of a solid-state laser, in which a Q-switch is "spontaneously" formed at the frequency of relaxation oscillations, has been observed for the first time. The new generation has been implemented by means of the previously proposed method of an acoustic modulator of a traveling wave in combination with a spherical mirror of a cavity. Stable pulse trains with a repetition frequency of ~30 kHz and a duration of ~2 µs have been observed in the diode-pump Nd:YAG laser with an average output power of ~3 W. Each train contains about 200 equispaced single pulses with a duration of ~45 ps.

  9. High resolution switching mode inductance-to-frequency converter with temperature compensation.

    Science.gov (United States)

    Matko, Vojko; Milanović, Miro

    2014-10-16

    This article proposes a novel method for the temperature-compensated inductance-to-frequency converter with a single quartz crystal oscillating in the switching oscillating circuit to achieve better temperature stability of the converter. The novelty of this method lies in the switching-mode converter, the use of additionally connected impedances in parallel to the shunt capacitances of the quartz crystal, and two inductances in series to the quartz crystal. This brings a considerable reduction of the temperature influence of AT-cut crystal frequency change in the temperature range between 10 and 40 °C. The oscillator switching method and the switching impedances connected to the quartz crystal do not only compensate for the crystal's natural temperature characteristics but also any other influences on the crystal such as ageing as well as from other oscillating circuit elements. In addition, the method also improves frequency sensitivity in inductance measurements. The experimental results show that through high temperature compensation improvement of the quartz crystal characteristics, this switching method theoretically enables a 2 pH resolution. It converts inductance to frequency in the range of 85-100 µH to 2-560 kHz.

  10. High Resolution Switching Mode Inductance-to-Frequency Converter with Temperature Compensation

    Directory of Open Access Journals (Sweden)

    Vojko Matko

    2014-10-01

    Full Text Available This article proposes a novel method for the temperature-compensated inductance-to-frequency converter with a single quartz crystal oscillating in the switching oscillating circuit to achieve better temperature stability of the converter. The novelty of this method lies in the switching-mode converter, the use of additionally connected impedances in parallel to the shunt capacitances of the quartz crystal, and two inductances in series to the quartz crystal. This brings a considerable reduction of the temperature influence of AT-cut crystal frequency change in the temperature range between 10 and 40 °C. The oscillator switching method and the switching impedances connected to the quartz crystal do not only compensate for the crystal’s natural temperature characteristics but also any other influences on the crystal such as ageing as well as from other oscillating circuit elements. In addition, the method also improves frequency sensitivity in inductance measurements. The experimental results show that through high temperature compensation improvement of the quartz crystal characteristics, this switching method theoretically enables a 2 pH resolution. It converts inductance to frequency in the range of 85–100 µH to 2–560 kHz.

  11. Topographical and electrochemical nanoscale imaging of living cells using voltage-switching mode scanning electrochemical microscopy

    Science.gov (United States)

    Takahashi, Yasufumi; Shevchuk, Andrew I.; Novak, Pavel; Babakinejad, Babak; Macpherson, Julie; Unwin, Patrick R.; Shiku, Hitoshi; Gorelik, Julia; Klenerman, David; Korchev, Yuri E.; Matsue, Tomokazu

    2012-01-01

    We describe voltage-switching mode scanning electrochemical microscopy (VSM-SECM), in which a single SECM tip electrode was used to acquire high-quality topographical and electrochemical images of living cells simultaneously. This was achieved by switching the applied voltage so as to change the faradaic current from a hindered diffusion feedback signal (for distance control and topographical imaging) to the electrochemical flux measurement of interest. This imaging method is robust, and a single nanoscale SECM electrode, which is simple to produce, is used for both topography and activity measurements. In order to minimize the delay at voltage switching, we used pyrolytic carbon nanoelectrodes with 6.5–100 nm radii that rapidly reached a steady-state current, typically in less than 20 ms for the largest electrodes and faster for smaller electrodes. In addition, these carbon nanoelectrodes are suitable for convoluted cell topography imaging because the RG value (ratio of overall probe diameter to active electrode diameter) is typically in the range of 1.5–3.0. We first evaluated the resolution of constant-current mode topography imaging using carbon nanoelectrodes. Next, we performed VSM-SECM measurements to visualize membrane proteins on A431 cells and to detect neurotransmitters from a PC12 cells. We also combined VSM-SECM with surface confocal microscopy to allow simultaneous fluorescence and topographical imaging. VSM-SECM opens up new opportunities in nanoscale chemical mapping at interfaces, and should find wide application in the physical and biological sciences. PMID:22611191

  12. Superluminescent high-efficient parametric generation in PPLN crystal with pumping by a Q-switched mode locked Nd:YAG laser

    Science.gov (United States)

    Donin, V. I.; Yakovin, D. V.; Yakovin, M. D.; Gribanov, A. V.

    2018-03-01

    We present results on parametric superluminescence in a periodically poled lithium niobate crystal pumped by a train of 45 ps pulses using a Q-switched mode locked Nd:YAG laser. The conversion efficiency (with respect to the absorbed power) was ~83%. To the best of our knowledge, this is the highest efficiency obtained with powerful superluminescent parametric sources. At the average pumping power of the laser of ~0.5 W and repetition rates of 1 and 1.7 kHz, the peak total output powers were as high as 210 and 200 kW, and the powers of the idler wavelength (3.82 µm) were 55 and 50 kW. New lines in the visible and UV spectrum were observed and are explained. The experiments demonstrated that the spectral and angular characteristics of superluminescence are determined by the pumping laser. In particular, the line width of the signal wave was close to that of the pumping line at ~200 GHz, and the divergence of the signal and idler waves depended only on the convergence (divergence) angle of the pumping radiation (30 mrad) and was independent of the wavelength.

  13. Balancing Audio

    DEFF Research Database (Denmark)

    Walther-Hansen, Mads

    2016-01-01

    This paper explores the concept of balance in music production and examines the role of conceptual metaphors in reasoning about audio editing. Balance may be the most central concept in record production, however, the way we cognitively understand and respond meaningfully to a mix requiring balance...... is not thoroughly understood. In this paper I treat balance as a metaphor that we use to reason about several different actions in music production, such as adjusting levels, editing the frequency spectrum or the spatiality of the recording. This study is based on an exploration of a linguistic corpus of sound...

  14. Semantic Audio Track Mixer

    OpenAIRE

    Uhle, C.; Herre, J.; Ridderbusch, F.; Popp, H.

    2011-01-01

    An audio mixer for mixing a plurality of audio tracks to a mixture signal comprises a semantic command interpreter (30; 35) for receiving a semantic mixing command and for deriving a plurality of mixing parameters for the plurality of audio tracks from the semantic mixing command; an audio track processor (70; 75) for processing the plurality of audio tracks in accordance with the plurality of mixing parameters; and an audio track combiner (76) for combining the plurality of audio tracks proc...

  15. Audio Restoration

    Science.gov (United States)

    Esquef, Paulo A. A.

    The first reproducible recording of human voice was made in 1877 on a tinfoil cylinder phonograph devised by Thomas A. Edison. Since then, much effort has been expended to find better ways to record and reproduce sounds. By the mid-1920s, the first electrical recordings appeared and gradually took over purely acoustic recordings. The development of electronic computers, in conjunction with the ability to record data onto magnetic or optical media, culminated in the standardization of compact disc format in 1980. Nowadays, digital technology is applied to several audio applications, not only to improve the quality of modern and old recording/reproduction techniques, but also to trade off sound quality for less storage space and less taxing transmission capacity requirements.

  16. Integrated power electronic converters and digital control

    CERN Document Server

    Emadi, Ali; Nie, Zhong

    2009-01-01

    Non-isolated DC-DC ConvertersBuck ConverterBoost ConverterBuck-Boost ConverterIsolated DC-DC ConvertersFlyback ConverterForward ConverterPush-Pull ConverterFull-Bridge ConverterHalf-Bridge ConverterPower Factor CorrectionConcept of PFCGeneral Classification of PFC CircuitsHigh Switching Frequency Topologies for PFCApplication of PFC in Advanced Motor DrivesIntegrated Switched-Mode Power ConvertersSwitched-Mode Power SuppliesThe Concept of Integrated ConverterDefinition of Integrated Switched-Mode Power Supplies (ISMPS)Boost-Type Integrated TopologiesGeneral Structure of Boost-Type Integrated T

  17. Intelligent audio analysis

    CERN Document Server

    Schuller, Björn W

    2013-01-01

    This book provides the reader with the knowledge necessary for comprehension of the field of Intelligent Audio Analysis. It firstly introduces standard methods and discusses the typical Intelligent Audio Analysis chain going from audio data to audio features to audio recognition.  Further, an introduction to audio source separation, and enhancement and robustness are given. After the introductory parts, the book shows several applications for the three types of audio: speech, music, and general sound. Each task is shortly introduced, followed by a description of the specific data and methods applied, experiments and results, and a conclusion for this specific task. The books provides benchmark results and standardized test-beds for a broader range of audio analysis tasks. The main focus thereby lies on the parallel advancement of realism in audio analysis, as too often today’s results are overly optimistic owing to idealized testing conditions, and it serves to stimulate synergies arising from transfer of ...

  18. A New Combined Boost Converter with Improved Voltage Gain as a Battery-Powered Front-End Interface for Automotive Audio Amplifiers

    Directory of Open Access Journals (Sweden)

    Ching-Ming Lai

    2017-08-01

    Full Text Available High boost DC/DC voltage conversion is always indispensable in a power electronic interface of certain battery-powered electrical equipment. However, a conventional boost converter works for a wide duty cycle for such high voltage gain, which increases power consumption and has low reliability problems. In order to solve this issue, a new battery-powered combined boost converter with an interleaved structure consisting of two phases used in automotive audio amplifier is presented. The first phase uses a conventional boost converter; the second phase employs the inverted type. With this architecture, a higher boost voltage gain is able to be achieved. A derivation of the operating principles of the converter, analyses of its topology, as well as a closed-loop control designs are performed in this study. Furthermore, simulations and experiments are also performed using input voltage of 12 V for a 120 W circuit. A reasonable duty cycle is selected to reach output voltage of 60 V, which corresponds to static voltage gain of five. The converter achieves a maximum measured conversion efficiency of 98.7% and the full load efficiency of 89.1%.

  19. Back to basics audio

    CERN Document Server

    Nathan, Julian

    1998-01-01

    Back to Basics Audio is a thorough, yet approachable handbook on audio electronics theory and equipment. The first part of the book discusses electrical and audio principles. Those principles form a basis for understanding the operation of equipment and systems, covered in the second section. Finally, the author addresses planning and installation of a home audio system.Julian Nathan joined the audio service and manufacturing industry in 1954 and moved into motion picture engineering and production in 1960. He installed and operated recording theaters in Sydney, Austra

  20. Switch-mode High Voltage Drivers for Dielectric Electro Active Polymer (DEAP) Incremental Actuators

    DEFF Research Database (Denmark)

    Thummala, Prasanth

    Actuators based on dielectric electro active polymers (DEAPs) have attracted special attention in the recent years. The unique characteristics of DEAP are large strain (5-100%), light weight (7 times lighter than steel and copper), high flexibility (100,000 times less stiff than steel), low noise...... operation, and low power consumption. DEAP actuators require very high voltage (2-2.5 kV) to fully elongate them. In general, the elongation or stroke length of a DEAP actuator is of the order of mm. DEAP actuators can be configured to provide incremental motion, thus overcoming the inherent size...

  1. Recommending audio mixing workflows

    OpenAIRE

    Sauer, Christian; Roth-Berghofer, Thomas; Auricchio, Nino; Proctor, Sam

    2013-01-01

    This paper describes our work on Audio Advisor, a workflow recommender for audio mixing. We examine the process of eliciting, formalising and modelling the domain knowledge and expert’s experience. We are also describing the effects and problems associated with the knowledge formalisation processes. We decided to employ structured case-based reasoning using the myCBR 3 to capture the vagueness encountered in the audio domain. We detail on how we used extensive similarity measure modelling to ...

  2. Design of High-Voltage Switch-Mode Power Amplifier Based on Digital-Controlled Hybrid Multilevel Converter

    OpenAIRE

    Hou, Yanbin; Sun, Wanrong; Ren, Aifeng; Liu, Shuming

    2016-01-01

    Compared with conventional Class-A, Class-B, and Class-AB amplifiers, Class-D amplifier, also known as switching amplifier, employs pulse width modulation (PWM) technology and solid-state switching devices, capable of achieving much higher efficiency. However, PWM-based switching amplifier is usually designed for low-voltage application, offering a maximum output voltage of several hundred Volts. Therefore, a step-up transformer is indispensably adopted in PWM-based Class-D amplifier to produ...

  3. Categorizing Video Game Audio

    DEFF Research Database (Denmark)

    Westerberg, Andreas Rytter; Schoenau-Fog, Henrik

    2015-01-01

    This paper dives into the subject of video game audio and how it can be categorized in order to deliver a message to a player in the most precise way. A new categorization, with a new take on the diegetic spaces, can be used a tool of inspiration for sound- and game-designers to rethink how...... they can use audio in video games. The conclusion of this study is that the current models' view of the diegetic spaces, used to categorize video game audio, is not t to categorize all sounds. This can however possibly be changed though a rethinking of how the player interprets audio....

  4. Roundtable Audio Discussion

    Directory of Open Access Journals (Sweden)

    Chris Bigum

    2007-01-01

    Full Text Available RoundTable on Technology, Teaching and Tools. This is a roundtable audio interview conducted by James Farmer, founder of Edublogs, with Anne Bartlett-Bragg (University of Technology Sydney and Chris Bigum (Deakin University. Skype was used to make and record the audio conference and the resulting sound file was edited by Andrew McLauchlan.

  5. Portable Audio Design

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh

    2014-01-01

    The chapter presents a methodological approach to the early process of producing portable audio design. The chapter high lights audio walks and audio guides, but can also be of inspiration when working with graphical and video production for portable devices. The final products can be presented...... within online and physical institutional contexts. The approach focuses especially on the relationship to specific sites, and how an awareness of the relationship between the site and the production can be part of the design process. Such awareness entails several approaches: the necessity of paying...

  6. Concept for audio encoding and decoding for audio channels and audio objects

    OpenAIRE

    Adami, Alexander; Borss, Christian; Dick, Sascha; Ertel, Christian; Füg, Simone; Herre, Jürgen; Hilpert, Johannes; Hölzer, Andreas; Kratschmer, Michael; Küch, Fabian; Kuntz, Achim; Murtaza, Adrian; Plogsties, Jan; Silzle, Andreas; Stenzel, Hanne

    2015-01-01

    Audio encoder for encoding audio input data (101) to obtain audio output data (501) comprises an input interface (100) for receiving a plurality of audio channels, a plurality of audio objects and metadata related to one or more of the plurality of audio objects; a mixer (200) for mixing the plurality of objects and the plurality of channels to obtain a plurality of pre-mixed channels, each pre-mixed channel comprising audio data of a channel and audio data of at least one object; a core enco...

  7. COMINT Audio Interface

    National Research Council Canada - National Science Library

    Morgans, D

    1999-01-01

    .... Demonstrations conducted under this effort concluded that 3D audio localization techniques on their own have not been developed to the point where they achieve the fidelity necessary for the military work environment...

  8. Structure Learning in Audio

    DEFF Research Database (Denmark)

    Nielsen, Andreas Brinch

    By having information about the setting a user is in, a computer is able to make decisions proactively to facilitate tasks for the user. Two approaches are taken in this thesis to achieve more information about an audio environment. One approach is that of classifying audio, and a new approach us......-Gaussian source distributions allowing a much wider use of the method. All methods uses a variety of classification models and model selection algorithms which is a common theme of the thesis....

  9. Museum audio description

    OpenAIRE

    Martins, Cláudia Susana Nunes

    2011-01-01

    Audio description for the blind and visually impaired has been around since people have described what is seen. Throughout time, it has evolved and developed within different media, starting with reality and daily life, moving into the cinema and television, then across other performing arts, museums and art galleries, and public places. Thus, academics and entertainment providers have developed a growing interest for audio description, especially in what concerns the best methods and strateg...

  10. Design and implementation of an audio indicator

    Science.gov (United States)

    Zheng, Shiyong; Li, Zhao; Li, Biqing

    2017-04-01

    This page proposed an audio indicator which designed by using C9014, LED by operational amplifier level indicator, the decimal count/distributor of CD4017. The experimental can control audibly neon and holiday lights through the signal. Input audio signal after C9014 composed of operational amplifier for power amplifier, the adjust potentiometer extraction amplification signal input voltage CD4017 distributors make its drive to count, then connect the LED display running situation of the circuit. This simple audio indicator just use only U1 and can produce two colors LED with the audio signal tandem come pursuit of the running effect, from LED display the running of the situation takes can understand the general audio signal. The variation in the audio and the frequency of the signal and the corresponding level size. In this light can achieve jump to change, slowly, atlas, lighting four forms, used in home, hotel, discos, theater, advertising and other fields, and a wide range of USES, rU1h life in a modern society.

  11. Audio-visual imposture

    Science.gov (United States)

    Karam, Walid; Mokbel, Chafic; Greige, Hanna; Chollet, Gerard

    2006-05-01

    A GMM based audio visual speaker verification system is described and an Active Appearance Model with a linear speaker transformation system is used to evaluate the robustness of the verification. An Active Appearance Model (AAM) is used to automatically locate and track a speaker's face in a video recording. A Gaussian Mixture Model (GMM) based classifier (BECARS) is used for face verification. GMM training and testing is accomplished on DCT based extracted features of the detected faces. On the audio side, speech features are extracted and used for speaker verification with the GMM based classifier. Fusion of both audio and video modalities for audio visual speaker verification is compared with face verification and speaker verification systems. To improve the robustness of the multimodal biometric identity verification system, an audio visual imposture system is envisioned. It consists of an automatic voice transformation technique that an impostor may use to assume the identity of an authorized client. Features of the transformed voice are then combined with the corresponding appearance features and fed into the GMM based system BECARS for training. An attempt is made to increase the acceptance rate of the impostor and to analyzing the robustness of the verification system. Experiments are being conducted on the BANCA database, with a prospect of experimenting on the newly developed PDAtabase developed within the scope of the SecurePhone project.

  12. Parametric Audio Based Decoder and Music Synthesizer for Mobile Applications

    NARCIS (Netherlands)

    Oomen, A.W.J.; Szczerba, M.Z.; Therssen, D.

    2011-01-01

    This paper reviews parametric audio coders and discusses novel technologies introduced in a low-complexity, low-power consumption audiodecoder and music synthesizer platform developed by the authors. Thedecoder uses parametric coding scheme based on the MPEG-4 Parametric Audio standard. In order to

  13. Perceptual Audio Hashing Functions

    Directory of Open Access Journals (Sweden)

    Emin Anarım

    2005-07-01

    Full Text Available Perceptual hash functions provide a tool for fast and reliable identification of content. We present new audio hash functions based on summarization of the time-frequency spectral characteristics of an audio document. The proposed hash functions are based on the periodicity series of the fundamental frequency and on singular-value description of the cepstral frequencies. They are found, on one hand, to perform very satisfactorily in identification and verification tests, and on the other hand, to be very resilient to a large variety of attacks. Moreover, we address the issue of security of hashes and propose a keying technique, and thereby a key-dependent hash function.

  14. DAFX Digital Audio Effects

    CERN Document Server

    2011-01-01

    The rapid development in various fields of Digital Audio Effects, or DAFX, has led to new algorithms and this second edition of the popular book, DAFX: Digital Audio Effects has been updated throughout to reflect progress in the field. It maintains a unique approach to DAFX with a lecture-style introduction into the basics of effect processing. Each effect description begins with the presentation of the physical and acoustical phenomena, an explanation of the signal processing techniques to achieve the effect, followed by a discussion of musical applications and the control of effect parameter

  15. Audio asymmetric watermarking technique

    OpenAIRE

    Furon, Teddy; Moreau, Nicolas; Duhamel, Pierre

    2000-01-01

    This paper presents the application of the promising public key watermarking method1 to the audio domain. Its de- tection process does not need the original content nor the secret key used in the embedding process. It is the trans- lation, in the watermarking domain, of a public key pair cryptosystem [1]. We start to build the detector with some basic assumptions. This leads to a hypothesis test based on probability likelihood. But real audio signals do not satisfy the assumption of a Gaussia...

  16. 3D Audio System

    Science.gov (United States)

    1992-01-01

    Ames Research Center research into virtual reality led to the development of the Convolvotron, a high speed digital audio processing system that delivers three-dimensional sound over headphones. It consists of a two-card set designed for use with a personal computer. The Convolvotron's primary application is presentation of 3D audio signals over headphones. Four independent sound sources are filtered with large time-varying filters that compensate for motion. The perceived location of the sound remains constant. Possible applications are in air traffic control towers or airplane cockpits, hearing and perception research and virtual reality development.

  17. Predistortion of a Bidirectional Cuk Audio Amplifier

    DEFF Research Database (Denmark)

    Birch, Thomas Hagen; Nielsen, Dennis; Knott, Arnold

    2014-01-01

    using predistortion. This paper suggests linearizing a nonlinear bidirectional Cuk audio amplifier using an analog predistortion approach. A prototype power stage was built and results show that a voltage gain of up to 9 dB and reduction in THD from 6% down to 3% was obtainable using this approach....

  18. Power enhancement of piezoelectric transformers for power supplies

    DEFF Research Database (Denmark)

    Ekhtiari, Marzieh; Steenstrup, Anders Resen; Zhang, Zhe

    2016-01-01

    This paper studies power enhancement of piezoelectric transformers to be used in inductorless, half-bridge, piezoelecteric-based switch mode power supplies for driving a piezo actuator motor system in a high strength magnetic environment for magnetic resonance imaging and computed tomography...

  19. Audio Feedback -- Better Feedback?

    Science.gov (United States)

    Voelkel, Susanne; Mello, Luciane V.

    2014-01-01

    National Student Survey (NSS) results show that many students are dissatisfied with the amount and quality of feedback they get for their work. This study reports on two case studies in which we tried to address these issues by introducing audio feedback to one undergraduate (UG) and one postgraduate (PG) class, respectively. In case study one…

  20. Circuit Bodging : Audio Multiplexer

    NARCIS (Netherlands)

    Roeling, E.; Allen, B.

    2010-01-01

    Audio amplifiers usually come with a single, glaring design flaw: Not enough auxiliary inputs. Not only that, but you’re usually required to press a button to switch between the amplifier’s limited number of inputs. This is unacceptable - we have better things to do than change input channels! In

  1. Embedded Audio Without Beeps

    DEFF Research Database (Denmark)

    Overholt, Daniel; Møbius, Nikolaj Friis

    2014-01-01

    software environments for audio processing) via innovative interfaces that send real-time inputs to such software running on a laptop, mobile device, or small Linux board (e.g., Raspberry Pi or Beagleboard). Basic hardware will be provided, but participants are also encouraged to bring related equipment...

  2. The audio expert everything you need to know about audio

    CERN Document Server

    Winer, Ethan

    2012-01-01

    The Audio Expert is a comprehensive reference that covers all aspects of audio, with many practical, as well as theoretical, explanations. Providing in-depth descriptions of how audio really works, using common sense plain-English explanations and mechanical analogies with minimal math, the book is written for people who want to understand audio at the deepest, most technical level, without needing an engineering degree. It's presented in an easy-to-read, conversational tone, and includes more than 400 figures and photos augmenting the text.The Audio Expert takes th

  3. Efectos digitales de audio con Web Audio API

    OpenAIRE

    GARCÍA CHAPARRO, SAMUEL

    2015-01-01

    El presente trabajo consiste en un estudio de la capacidad de Web Audio API para el procesado de efectos de audio en tiempo real. De todos los efectos de audio posibles se han elegido el wah-wah, el flanger y el choris, efectos ampliamente empleados con guitarra eléctrica. Se crean funciones de lenguaje JavaScript que modelan el comportamiento de los efectos de audio elegidos, haciéndolas funcionar sobre una plataforma web HTML5. García Chaparro, S. (2015). Efectos digitales de audio con W...

  4. ENERGY STAR Certified Audio Video

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Audio Video Equipment that are effective as of May 1, 2013. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=audio_dvd.pr_crit_audio_dvd

  5. Optimizing design of converters using power cycling lifetime models

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Ørndrup; Munk-Nielsen, Stig

    2015-01-01

    Converter power cycling lifetime depends heavily on converter operation point. A lifetime model of a single power module switched mode power supply with wide input voltage range is shown. A lifetime model is created using a power loss model, a thermal model and a model for power cycling capability...

  6. Audible Aliasing Distortion in Digital Audio Synthesis

    Directory of Open Access Journals (Sweden)

    J. Schimmel

    2012-04-01

    Full Text Available This paper deals with aliasing distortion in digital audio signal synthesis of classic periodic waveforms with infinite Fourier series, for electronic musical instruments. When these waveforms are generated in the digital domain then the aliasing appears due to its unlimited bandwidth. There are several techniques for the synthesis of these signals that have been designed to avoid or reduce the aliasing distortion. However, these techniques have high computing demands. One can say that today's computers have enough computing power to use these methods. However, we have to realize that today’s computer-aided music production requires tens of multi-timbre voices generated simultaneously by software synthesizers and the most of the computing power must be reserved for hard-disc recording subsystem and real-time audio processing of many audio channels with a lot of audio effects. Trivially generated classic analog synthesizer waveforms are therefore still effective for sound synthesis. We cannot avoid the aliasing distortion but spectral components produced by the aliasing can be masked with harmonic components and thus made inaudible if sufficient oversampling ratio is used. This paper deals with the assessment of audible aliasing distortion with the help of a psychoacoustic model of simultaneous masking and compares the computing demands of trivial generation using oversampling with those of other methods.

  7. Class D audio amplifiers for high voltage capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis

    Audio reproduction systems contains two key components, the amplifier and the loudspeaker. In the last 20 – 30 years the technology of audio amplifiers have performed a fundamental shift of paradigm. Class D audio amplifiers have replaced the linear amplifiers, suffering from the well-known issues...... of high volume, weight, and cost. High efficient class D amplifiers are now widely available offering power densities, that their linear counterparts can not match. Unlike the technology of audio amplifiers, the loudspeaker is still based on the traditional electrodynamic transducer invented by C.W. Rice...... and E.W. Kellog in 1925 [1]. The poor efficiency of the electrodynamic transducer remains a key issue, and a significant limit of the efficiency of the complete audio reproduction systems. Also the geometric limits of the electrodynamic transducer imposes significant limits on the design of loudspeakers...

  8. Efficient audio signal processing for embedded systems

    Science.gov (United States)

    Chiu, Leung Kin

    As mobile platforms continue to pack on more computational power, electronics manufacturers start to differentiate their products by enhancing the audio features. However, consumers also demand smaller devices that could operate for longer time, hence imposing design constraints. In this research, we investigate two design strategies that would allow us to efficiently process audio signals on embedded systems such as mobile phones and portable electronics. In the first strategy, we exploit properties of the human auditory system to process audio signals. We designed a sound enhancement algorithm to make piezoelectric loudspeakers sound ”richer" and "fuller." Piezoelectric speakers have a small form factor but exhibit poor response in the low-frequency region. In the algorithm, we combine psychoacoustic bass extension and dynamic range compression to improve the perceived bass coming out from the tiny speakers. We also developed an audio energy reduction algorithm for loudspeaker power management. The perceptually transparent algorithm extends the battery life of mobile devices and prevents thermal damage in speakers. This method is similar to audio compression algorithms, which encode audio signals in such a ways that the compression artifacts are not easily perceivable. Instead of reducing the storage space, however, we suppress the audio contents that are below the hearing threshold, therefore reducing the signal energy. In the second strategy, we use low-power analog circuits to process the signal before digitizing it. We designed an analog front-end for sound detection and implemented it on a field programmable analog array (FPAA). The system is an example of an analog-to-information converter. The sound classifier front-end can be used in a wide range of applications because programmable floating-gate transistors are employed to store classifier weights. Moreover, we incorporated a feature selection algorithm to simplify the analog front-end. A machine

  9. Audio Signal Decoder, Method for Decoding an Audio Signal and Computer Program Using Cascaded Audio Object Processing Stages

    OpenAIRE

    Hellmuth, O.; Falch, C.; Herre, J.; Hilpert, J.; Ridderbusch, F.; Terentiev, L.

    2010-01-01

    An audio signal decoder for providing an upmix signal representation in dependence on a downmix signal representation and an object-related parametric information comprises an object separator configured to decompose the downmix signal representation, to provide a first audio information describing a first set of one or more audio objects of a first audio object type and a second audio information describing a second set of one or more audio objects of a second audio object type, in dependenc...

  10. Efficiency Optimization in Class-D Audio Amplifiers

    DEFF Research Database (Denmark)

    Yamauchi, Akira; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2015-01-01

    This paper presents a new power efficiency optimization routine for designing Class-D audio amplifiers. The proposed optimization procedure finds design parameters for the power stage and the output filter, and the optimum switching frequency such that the weighted power losses are minimized under...... the given constraints. The optimization routine is applied to minimize the power losses in a 130 W class-D audio amplifier based on consumer behavior investigations, where the amplifier operates at idle and low power levels most of the time. Experimental results demonstrate that the optimization method can...... lead to around 30 % of efficiency improvement at 1.3 W output power without significant effects on both audio performance and the efficiency at high power levels....

  11. Small signal audio design

    CERN Document Server

    Self, Douglas

    2014-01-01

    Learn to use inexpensive and readily available parts to obtain state-of-the-art performance in all the vital parameters of noise, distortion, crosstalk and so on. With ample coverage of preamplifiers and mixers and a new chapter on headphone amplifiers, this practical handbook provides an extensive repertoire of circuits that can be put together to make almost any type of audio system.A resource packed full of valuable information, with virtually every page revealing nuggets of specialized knowledge not found elsewhere. Essential points of theory that bear on practical performance are lucidly

  12. Tag Based Audio Search Engine

    OpenAIRE

    Parameswaran Vellachu; Sunitha Abburu

    2012-01-01

    The volume of the music database is increasing day by day. Getting the required song as per the choice of the listener is a big challenge. Hence, it is really hard to manage this huge quantity, in terms of searching, filtering, through the music database. It is surprising to see that the audio and music industry still rely on very simplistic metadata to describe music files. However, while searching audio resource, an efficient "Tag Based Audio Search Engine" is necessary. The current researc...

  13. Mixxing Audio Menggunakan FL Studio

    OpenAIRE

    Prawira, Yanheri

    2011-01-01

    Kajian ini bertujuan untuk memudahkan proses mixing audio dan menghemat biaya dalam proses Mixxing audio hanya menggunakan sebuah laptop ataupun komputer sebagai media utama yang menggunakan OS Windows 7, dan menggunakan aplikasi yang mencakup : FL Studio 9, ASIO 4 ALL tanpa tambahan alat apapun. Tujuan dari pembuatan system ini berguna untuk mempermudah proses mixxing audio DJ dengan menggunakan media laptop ataupun komputer, tanpa mengeluarkan banyak biaya. 082406014

  14. Parametric Coding of Stereo Audio

    Directory of Open Access Journals (Sweden)

    Erik Schuijers

    2005-06-01

    Full Text Available Parametric-stereo coding is a technique to efficiently code a stereo audio signal as a monaural signal plus a small amount of parametric overhead to describe the stereo image. The stereo properties are analyzed, encoded, and reinstated in a decoder according to spatial psychoacoustical principles. The monaural signal can be encoded using any (conventional audio coder. Experiments show that the parameterized description of spatial properties enables a highly efficient, high-quality stereo audio representation.

  15. Differences in Human Audio Localization Performance between a HRTF- and a non-HRTF Audio System

    DEFF Research Database (Denmark)

    Larsen, Camilla Horne; Lauritsen, David Skødt; Larsen, Jacob Junker

    2013-01-01

    Spatial audio solutions have been around for a long time in real-time applications, but yielding spatial cues that more closely simulate real life accuracy has been a computational issue, and has often been solved by hardware solutions. This has long been a restriction, but now with more powerful...... computers this is becoming a lesser and lesser concern and software solutions are now applicable. Most current virtual environment applications do not take advantage of these im- plementations of accurate spatial cues, however. This paper compares a common implementation of spatial audio and a head......-related transfer function (HRTF) system implemen- tation in a study in relation to precision, speed and navi- gational performance in localizing audio sources in a virtual environment. We found that a system using HRTFs is signif- icantly better at all three performance tasks than a system using panning....

  16. Aurally Aided Visual Search Performance Comparing Virtual Audio Systems

    DEFF Research Database (Denmark)

    Larsen, Camilla Horne; Lauritsen, David Skødt; Larsen, Jacob Junker

    2014-01-01

    Due to increased computational power reproducing binaural hearing in real-time applications, through usage of head-related transfer functions (HRTFs), is now possible. This paper addresses the differences in aurally-aided visual search performance between an HRTF enhanced audio system (3D...... with white dots. The results indicate that 3D audio yields faster search latencies than panning audio, especially with larger amounts of distractors. The applications of this research could fit virtual environments such as video games or virtual simulations....

  17. Aurally Aided Visual Search Performance Comparing Virtual Audio Systems

    DEFF Research Database (Denmark)

    Larsen, Camilla Horne; Lauritsen, David Skødt; Larsen, Jacob Junker

    2014-01-01

    Due to increased computational power, reproducing binaural hearing in real-time applications, through usage of head-related transfer functions (HRTFs), is now possible. This paper addresses the differences in aurally-aided visual search performance between a HRTF enhanced audio system (3D...... with white dots. The results indicate that 3D audio yields faster search latencies than panning audio, especially with larger amounts of distractors. The applications of this research could fit virtual environments such as video games or virtual simulations....

  18. The Lowdown on Audio Downloads

    Science.gov (United States)

    Farrell, Beth

    2010-01-01

    First offered to public libraries in 2004, downloadable audiobooks have grown by leaps and bounds. According to the Audio Publishers Association, their sales today account for 21% of the spoken-word audio market. It hasn't been easy, however. WMA. DRM. MP3. AAC. File extensions small on letters but very big on consequences for librarians,…

  19. Instrumental Landing Using Audio Indication

    Science.gov (United States)

    Burlak, E. A.; Nabatchikov, A. M.; Korsun, O. N.

    2018-02-01

    The paper proposes an audio indication method for presenting to a pilot the information regarding the relative positions of an aircraft in the tasks of precision piloting. The implementation of the method is presented, the use of such parameters of audio signal as loudness, frequency and modulation are discussed. To confirm the operability of the audio indication channel the experiments using modern aircraft simulation facility were carried out. The simulated performed the instrument landing using the proposed audio method to indicate the aircraft deviations in relation to the slide path. The results proved compatible with the simulated instrumental landings using the traditional glidescope pointers. It inspires to develop the method in order to solve other precision piloting tasks.

  20. A centralized audio presentation manager

    Energy Technology Data Exchange (ETDEWEB)

    Papp, A.L. III; Blattner, M.M.

    1994-05-16

    The centralized audio presentation manager addresses the problems which occur when multiple programs running simultaneously attempt to use the audio output of a computer system. Time dependence of sound means that certain auditory messages must be scheduled simultaneously, which can lead to perceptual problems due to psychoacoustic phenomena. Furthermore, the combination of speech and nonspeech audio is examined; each presents its own problems of perceptibility in an acoustic environment composed of multiple auditory streams. The centralized audio presentation manager receives abstract parameterized message requests from the currently running programs, and attempts to create and present a sonic representation in the most perceptible manner through the use of a theoretically and empirically designed rule set.

  1. WLAN Technologies for Audio Delivery

    Directory of Open Access Journals (Sweden)

    Nicolas-Alexander Tatlas

    2007-01-01

    Full Text Available Audio delivery and reproduction for home or professional applications may greatly benefit from the adoption of digital wireless local area network (WLAN technologies. The most challenging aspect of such integration relates the synchronized and robust real-time streaming of multiple audio channels to multipoint receivers, for example, wireless active speakers. Here, it is shown that current WLAN solutions are susceptible to transmission errors. A detailed study of the IEEE802.11e protocol (currently under ratification is also presented and all relevant distortions are assessed via an analytical and experimental methodology. A novel synchronization scheme is also introduced, allowing optimized playback for multiple receivers. The perceptual audio performance is assessed for both stereo and 5-channel applications based on either PCM or compressed audio signals.

  2. Definici?n de audio

    OpenAIRE

    Monta?ez, Luis A.; Cabrera, Juan G.

    2015-01-01

    Descripci?n del significado de Audio como objeto de estudio por distintos autores, y su diferenciaci?n con el significado de Sonido. Se define Audio como una se?al el?ctrica con caracter?sticas similares en su forma de onda en comparaci?n a la de una se?al sonora. La se?al sonora corresponde a presi?n en un medio f?sico, mientras que la se?al de Audio es una tensi?n o voltaje definida como se?al an?loga. As? el Audio se concibe como una se?al el?ctrica, an?loga o anal?gica, frente una se?al s...

  3. Definici?n de audio

    OpenAIRE

    Monta?ez Carrillo, Luis A.; Cabrera, Juan G.

    2015-01-01

    Descripci?n del significado de Audio como objeto de estudio por distintos autores, y su diferenciaci?n con el significado de Sonido. De esta forma se define Audio como una se?al el?ctrica con caracter?sticas similares en su forma de onda en comparaci?n a la de una se?al sonora, teniendo en cuenta la se?al sonora corresponde a presi?n en u medio f?sico, mientras que la se?al de Audio es una tensi?n o voltaje definida como se?al an?loga. En este orden de ideas, el Audio se concibe como una se?a...

  4. ENERGY STAR Certified Audio Video

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Audio Video Equipment that are effective as of...

  5. Musical examination to bridge audio data and sheet music

    Science.gov (United States)

    Pan, Xunyu; Cross, Timothy J.; Xiao, Liangliang; Hei, Xiali

    2015-03-01

    useful for teaching music lessons on the web. The developed system is evaluated with songs played with guitar, keyboard, violin, and other popular musical instruments (primarily electronic or stringed instruments). The Musicians Aid system is successful at both representing and analyzing audio data and it is also powerful in assisting individuals interested in learning and understanding music.

  6. Perceptually controlled doping for audio source separation

    Science.gov (United States)

    Mahé, Gaël; Nadalin, Everton Z.; Suyama, Ricardo; Romano, João MT

    2014-12-01

    The separation of an underdetermined audio mixture can be performed through sparse component analysis (SCA) that relies however on the strong hypothesis that source signals are sparse in some domain. To overcome this difficulty in the case where the original sources are available before the mixing process, the informed source separation (ISS) embeds in the mixture a watermark, which information can help a further separation. Though powerful, this technique is generally specific to a particular mixing setup and may be compromised by an additional bitrate compression stage. Thus, instead of watermarking, we propose a `doping' method that makes the time-frequency representation of each source more sparse, while preserving its audio quality. This method is based on an iterative decrease of the distance between the distribution of the signal and a target sparse distribution, under a perceptual constraint. We aim to show that the proposed approach is robust to audio coding and that the use of the sparsified signals improves the source separation, in comparison with the original sources. In this work, the analysis is made only in instantaneous mixtures and focused on voice sources.

  7. Realtime Audio with Garbage Collection

    OpenAIRE

    Matheussen, Kjetil Svalastog

    2010-01-01

    Two non-moving concurrent garbage collectors tailored for realtime audio processing are described. Both collectors work on copies of the heap to avoid cache misses and audio-disruptive synchronizations. Both collectors are targeted at multiprocessor personal computers. The first garbage collector works in uncooperative environments, and can replace Hans Boehm's conservative garbage collector for C and C++. The collector does not access the virtual memory system. Neither doe...

  8. Tourism research and audio methods

    DEFF Research Database (Denmark)

    Jensen, Martin Trandberg

    2016-01-01

    Audio methods enriches sensuous tourism ethnographies. • The note suggests five research avenues for future auditory scholarship. • Sensuous tourism research has neglected the role of sounds in embodied tourism experiences.......• Audio methods enriches sensuous tourism ethnographies. • The note suggests five research avenues for future auditory scholarship. • Sensuous tourism research has neglected the role of sounds in embodied tourism experiences....

  9. Audio Steganography with Embedded Text

    Science.gov (United States)

    Teck Jian, Chua; Chai Wen, Chuah; Rahman, Nurul Hidayah Binti Ab.; Hamid, Isredza Rahmi Binti A.

    2017-08-01

    Audio steganography is about hiding the secret message into the audio. It is a technique uses to secure the transmission of secret information or hide their existence. It also may provide confidentiality to secret message if the message is encrypted. To date most of the steganography software such as Mp3Stego and DeepSound use block cipher such as Advanced Encryption Standard or Data Encryption Standard to encrypt the secret message. It is a good practice for security. However, the encrypted message may become too long to embed in audio and cause distortion of cover audio if the secret message is too long. Hence, there is a need to encrypt the message with stream cipher before embedding the message into the audio. This is because stream cipher provides bit by bit encryption meanwhile block cipher provide a fixed length of bits encryption which result a longer output compare to stream cipher. Hence, an audio steganography with embedding text with Rivest Cipher 4 encryption cipher is design, develop and test in this project.

  10. Modeling Audio Fingerprints : Structure, Distortion, Capacity

    NARCIS (Netherlands)

    Doets, P.J.O.

    2010-01-01

    An audio fingerprint is a compact low-level representation of a multimedia signal. An audio fingerprint can be used to identify audio files or fragments in a reliable way. The use of audio fingerprints for identification consists of two phases. In the enrollment phase known content is fingerprinted,

  11. Introduction to audio analysis a MATLAB approach

    CERN Document Server

    Giannakopoulos, Theodoros

    2014-01-01

    Introduction to Audio Analysis serves as a standalone introduction to audio analysis, providing theoretical background to many state-of-the-art techniques. It covers the essential theory necessary to develop audio engineering applications, but also uses programming techniques, notably MATLAB®, to take a more applied approach to the topic. Basic theory and reproducible experiments are combined to demonstrate theoretical concepts from a practical point of view and provide a solid foundation in the field of audio analysis. Audio feature extraction, audio classification, audio segmentation, au

  12. Penerapan Audio Amplifier Stereo Untuk Beban Bersama Dan Bergantian Dengan Menggunakan Saklar Ganda Sebagai Pengatur Beban

    OpenAIRE

    Hidayat, Rahmat

    2013-01-01

    — Driver audio amplifier mempunyai fungsi sebagai penguat penggerak yaitu menggerakkan daya isyarat masukan dan meneruskan ke bagian penguat akhir (power amplifier).Perangkat audio sangatlah penting, dimana penggunaannya sangat luas. Terutama digunakan untuk memungkinkan seseorang untuk mengatasi publik yang luas. Penguat audio atau alat penguat bunyi adalah penguat elektonik yang digunakan untuk menguatkansinyal bunyi yang berfrekuensi rendah hingga ke tingkat yang bersesuaian untuk menggera...

  13. Predistortion of a Bidirectional Cuk Audio Amplifier

    DEFF Research Database (Denmark)

    Birch, Thomas Hagen; Nielsen, Dennis; Knott, Arnold

    2014-01-01

    Some non-linear amplifier topologies are capable of providing a larger voltage gain than one from a DC source, which could make them suitable for various applications. However, the non-linearities introduce a significant amount of harmonic distortion (THD). Some of this distortion could be reduced...... using predistortion. This paper suggests linearizing a nonlinear bidirectional Cuk audio amplifier using an analog predistortion approach. A prototype power stage was built and results show that a voltage gain of up to 9 dB and reduction in THD from 6% down to 3% was obtainable using this approach....

  14. Location audio simplified capturing your audio and your audience

    CERN Document Server

    Miles, Dean

    2014-01-01

    From the basics of using camera, handheld, lavalier, and shotgun microphones to camera calibration and mixer set-ups, Location Audio Simplified unlocks the secrets to clean and clear broadcast quality audio no matter what challenges you face. Author Dean Miles applies his twenty-plus years of experience as a professional location operator to teach the skills, techniques, tips, and secrets needed to produce high-quality production sound on location. Humorous and thoroughly practical, the book covers a wide array of topics, such as:* location selection* field mixing* boo

  15. A Joint Audio-Visual Approach to Audio Localization

    DEFF Research Database (Denmark)

    Jensen, Jesper Rindom; Christensen, Mads Græsbøll

    2015-01-01

    Localization of audio sources is an important research problem, e.g., to facilitate noise reduction. In the recent years, the problem has been tackled using distributed microphone arrays (DMA). A common approach is to apply direction-of-arrival (DOA) estimation on each array (denoted as nodes...... time-of-flight cameras. Moreover, we propose an optimal method for weighting such DOA and range information for audio localization. Our experiments on both synthetic and real data show that there is a clear, potential advantage of using the joint audiovisual localization framework....

  16. Audio-Visual Fusion for Sound Source Localization and Improved Attention

    International Nuclear Information System (INIS)

    Lee, Byoung Gi; Choi, Jong Suk; Yoon, Sang Suk; Choi, Mun Taek; Kim, Mun Sang; Kim, Dai Jin

    2011-01-01

    Service robots are equipped with various sensors such as vision camera, sonar sensor, laser scanner, and microphones. Although these sensors have their own functions, some of them can be made to work together and perform more complicated functions. AudioFvisual fusion is a typical and powerful combination of audio and video sensors, because audio information is complementary to visual information and vice versa. Human beings also mainly depend on visual and auditory information in their daily life. In this paper, we conduct two studies using audioFvision fusion: one is on enhancing the performance of sound localization, and the other is on improving robot attention through sound localization and face detection

  17. On the Myth of Pulse Width Modulated Spectrum in Theory and Practice

    DEFF Research Database (Denmark)

    Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael Andreas E.

    2009-01-01

    approaches by comparing them with reality from both the time and the frequency domain perspective. For validation a switch-mode audio power amplifier was built, delivering the contents material with less than 0.06 % distortion across the audio band at 50 W. The switch-mode signals have been evaluated very......Switch-mode audio power amplifiers are commonly used in sound reproduction. Their well known drawback is the radiation of high frequent energy, which can disturb radio and TV receivers. The designer of switch-mode audio equipment therefore needs to make arrangements to prevent this coupling which...... would otherwise result in bad audio performance. A deep understanding of the pulse width modulated (PWM) signal is therefore essential, which resulted in different mythic models as pulse, trapezoidal or Double Fourier Series (DFS) representations in the past. This paper will clarify these theoretical...

  18. Safety of power transformers, power supplies, reactors and similar products - Part 1: General requirements and tests

    CERN Document Server

    International Electrotechnical Commission. Geneva

    1998-01-01

    This International Standard deals with safety aspects of power transformers, power supplies, reactors and similar products such as electrical, thermal and mechanical safety. This standard covers the following types of dry-type transformers, power supplies, including switch mode power supplies, and reactors, the windings of which may be encapsulated or non-encapsulated. It has the status of a group safety publication in accordance with IEC Guide 104.

  19. Digital Augmented Reality Audio Headset

    Directory of Open Access Journals (Sweden)

    Jussi Rämö

    2012-01-01

    Full Text Available Augmented reality audio (ARA combines virtual sound sources with the real sonic environment of the user. An ARA system can be realized with a headset containing binaural microphones. Ideally, the ARA headset should be acoustically transparent, that is, it should not cause audible modification to the surrounding sound. A practical implementation of an ARA mixer requires a low-latency headphone reproduction system with additional equalization to compensate for the attenuation and the modified ear canal resonances caused by the headphones. This paper proposes digital IIR filters to realize the required equalization and evaluates a real-time prototype ARA system. Measurements show that the throughput latency of the digital prototype ARA system can be less than 1.4 ms, which is sufficiently small in practice. When the direct and processed sounds are combined in the ear, a comb filtering effect is brought about and appears as notches in the frequency response. The comb filter effect in speech and music signals was studied in a listening test and it was found to be inaudible when the attenuation is 20 dB. Insert ARA headphones have a sufficient attenuation at frequencies above about 1 kHz. The proposed digital ARA system enables several immersive audio applications, such as a virtual audio tourist guide and audio teleconferencing.

  20. Engaging Students with Audio Feedback

    Science.gov (United States)

    Cann, Alan

    2014-01-01

    Students express widespread dissatisfaction with academic feedback. Teaching staff perceive a frequent lack of student engagement with written feedback, much of which goes uncollected or unread. Published evidence shows that audio feedback is highly acceptable to students but is underused. This paper explores methods to produce and deliver audio…

  1. Haptic and Audio Interaction Design

    DEFF Research Database (Denmark)

    This book constitutes the refereed proceedings of the 5th International Workshop on Haptic and Audio Interaction Design, HAID 2010 held in Copenhagen, Denmark, in September 2010. The 21 revised full papers presented were carefully reviewed and selected for inclusion in the book. The papers are or...

  2. Audio watermark a comprehensive foundation using Matlab

    CERN Document Server

    Lin, Yiqing

    2015-01-01

    This book illustrates the commonly used and novel approaches of audio watermarking for copyrights protection. The author examines the theoretical and practical step by step guide to the topic of data hiding in audio signal such as music, speech, broadcast. The book covers new techniques developed by the authors are fully explained and MATLAB programs, for audio watermarking and audio quality assessments and also discusses methods for objectively predicting the perceptual quality of the watermarked audio signals. Explains the theoretical basics of the commonly used audio watermarking techniques Discusses the methods used to objectively and subjectively assess the quality of the audio signals Provides a comprehensive well tested MATLAB programs that can be used efficiently to watermark any audio media

  3. Audio signal recognition for speech, music, and environmental sounds

    Science.gov (United States)

    Ellis, Daniel P. W.

    2003-10-01

    Human listeners are very good at all kinds of sound detection and identification tasks, from understanding heavily accented speech to noticing a ringing phone underneath music playing at full blast. Efforts to duplicate these abilities on computer have been particularly intense in the area of speech recognition, and it is instructive to review which approaches have proved most powerful, and which major problems still remain. The features and models developed for speech have found applications in other audio recognition tasks, including musical signal analysis, and the problems of analyzing the general ``ambient'' audio that might be encountered by an auditorily endowed robot. This talk will briefly review statistical pattern recognition for audio signals, giving examples in several of these domains. Particular emphasis will be given to common aspects and lessons learned.

  4. Image and audio wavelet integration for home security video compression

    Science.gov (United States)

    Cheng, Yu-Shen; Huang, Gen-Dow

    2002-03-01

    We present a novel wavelet compression algorithm for both audio and image with acceptable test by human perception. It is well known that Discrete Wavelet Transform (DWT) provides global multiple resolution decomposition that is the significant feature for the audio and image compressions. Experimental simulations show that the proposed audio and image model can satisfy the current industrial communication requirements in terms of the processing time and the compression fidelity. Development of wavelet-based compression algorithm considers the trade-off for hardware implementations. As a result, this high-performance video codec can develop compact, low power, high-speed, portable, cost-effective, and low-weight video compression for multimedia and home security applications.

  5. Bit rates in audio source coding

    NARCIS (Netherlands)

    Veldhuis, Raymond N.J.

    1992-01-01

    The goal is to introduce and solve the audio coding optimization problem. Psychoacoustic results such as masking and excitation pattern models are combined with results from rate distortion theory to formulate the audio coding optimization problem. The solution of the audio optimization problem is a

  6. Audio Frequency Analysis in Mobile Phones

    Science.gov (United States)

    Aguilar, Horacio Munguía

    2016-01-01

    A new experiment using mobile phones is proposed in which its audio frequency response is analyzed using the audio port for inputting external signal and getting a measurable output. This experiment shows how the limited audio bandwidth used in mobile telephony is the main cause of the poor speech quality in this service. A brief discussion is…

  7. 50 CFR 27.72 - Audio equipment.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Audio equipment. 27.72 Section 27.72 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE... Audio equipment. The operation or use of audio devices including radios, recording and playback devices...

  8. Audio Satellites – Overhearing Everyday Life

    DEFF Research Database (Denmark)

    Breinbjerg, Morten; Højlund, Marie Koldkjær; Riis, Morten S.

    2016-01-01

    The project “Audio Satellites – overhearing everyday life” consists of a number of mobile listening devices (audio satellites) from which sound is distributed in real time to a server and made available for listening and mixing through a web interface. The audio satellites can either be carried...

  9. 36 CFR 2.12 - Audio disturbances.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Audio disturbances. 2.12... RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 2.12 Audio disturbances. (a) The following are prohibited..., motorized toy, or an audio device, such as a radio, television set, tape deck or musical instrument, in a...

  10. Audio-Visual Technician | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Occasionally records on audio and/or video media, conferences, seminars, lectures and other events. Edits and duplicates audio and video tapes ... Participates in the planning and design of new or updated audio-visual systems by providing technical input on system needs. Based on current and emerging requirements as ...

  11. Evaluating Visual Information Provided by Audio Description.

    Science.gov (United States)

    Peli, E.; And Others

    1996-01-01

    The video and standard audio portions of 2 television programs were presented to 25 adults with low vision and 24 adults with normal vision; 29 additional subjects only heard the standard audio portions. Subjects then answered questions based on audio descriptions (AD) provided by Descriptive Video Service. Results indicated that some AD…

  12. Teaching Behavioral Modeling and Simulation Techniques for Power Electronics Courses

    Science.gov (United States)

    Abramovitz, A.

    2011-01-01

    This paper suggests a pedagogical approach to teaching the subject of behavioral modeling of switch-mode power electronics systems through simulation by general-purpose electronic circuit simulators. The methodology is oriented toward electrical engineering (EE) students at the undergraduate level, enrolled in courses such as "Power…

  13. Audio Format Change From Analog to Digital Audio Using the Sony Sound Forge 9.0

    OpenAIRE

    Faisal Safrudin; Yulina Yulina, SKom, MMSI

    2007-01-01

    Changes in an audio analog to digital audio is not only useful in among the journalists or the journalists are also useful for general audiences though. In previous technology we encounter a lot of almost everyone uses the form of analog audio cassettes. Along with the development of technology, analog audio format is rarely used in the presence of digital audio, but it can be overcome by changing the format of analog audio to digital audio using Sony Sound Forge 9.0. The author will discuss ...

  14. Semantic Labeling of Nonspeech Audio Clips

    Directory of Open Access Journals (Sweden)

    Xiaojuan Ma

    2010-01-01

    Full Text Available Human communication about entities and events is primarily linguistic in nature. While visual representations of information are shown to be highly effective as well, relatively little is known about the communicative power of auditory nonlinguistic representations. We created a collection of short nonlinguistic auditory clips encoding familiar human activities, objects, animals, natural phenomena, machinery, and social scenes. We presented these sounds to a broad spectrum of anonymous human workers using Amazon Mechanical Turk and collected verbal sound labels. We analyzed the human labels in terms of their lexical and semantic properties to ascertain that the audio clips do evoke the information suggested by their pre-defined captions. We then measured the agreement with the semantically compatible labels for each sound clip. Finally, we examined which kinds of entities and events, when captured by nonlinguistic acoustic clips, appear to be well-suited to elicit information for communication, and which ones are less discriminable. Our work is set against the broader goal of creating resources that facilitate communication for people with some types of language loss. Furthermore, our data should prove useful for future research in machine analysis/synthesis of audio, such as computational auditory scene analysis, and annotating/querying large collections of sound effects.

  15. Teaching Power Electronics with a Design-Oriented, Project-Based Learning Method at the Technical University of Denmark

    Science.gov (United States)

    Zhang, Zhe; Hansen, Claus Thorp; Andersen, Michael A. E.

    2016-01-01

    Power electronics is a fast-developing technology within the electrical engineering field. This paper presents the results and experiences gained from applying design-oriented project-based learning to switch-mode power supply design in a power electronics course at the Technical University of Denmark (DTU). Project-based learning (PBL) is known…

  16. Analog Audio Format Changes From Being Digital Audio Using Sony Sound Forge 9.0

    OpenAIRE

    Faisal Safrudin; Yulina Yulina

    2010-01-01

    Perubahan sebuah audio analog ke audio digital tidak hanya berguna padakalangan jurnalis atau wartawan juga bermanfaat untuk khalayak umumsekalipun. Pada teknologi sebelumnya banyak kita jumpai hampir setiap orangmenggunakan audio analog yaitu berupa kaset. Sejalannya perkembanganteknologi, format audio analog sudah jarang digunakan dengan hadirnya audiodigital, namun hal tersebut dapat diatasi dengan merubah format audio analog keaudio digital dengan menggunakan Sony Sound Forge 9.0. Penulis...

  17. Implementation of a Dual on Die 140 V Super-Junction Power Transistors

    DEFF Research Database (Denmark)

    Nour, Yasser; Knott, Arnold; Jørgensen, Ivan Harald Holger

    Increasing the switching frequency for switch mode power supplies is one method to achieve smaller, lighter weight and hopefully cheaper power converters. Silicon is not only the dominant material used to produce the switches but also it allows more circuitry to be easily integrated on the same d...

  18. Audio-visual interactions in environment assessment.

    Science.gov (United States)

    Preis, Anna; Kociński, Jędrzej; Hafke-Dys, Honorata; Wrzosek, Małgorzata

    2015-08-01

    The aim of the study was to examine how visual and audio information influences audio-visual environment assessment. Original audio-visual recordings were made at seven different places in the city of Poznań. Participants of the psychophysical experiments were asked to rate, on a numerical standardized scale, the degree of comfort they would feel if they were in such an environment. The assessments of audio-visual comfort were carried out in a laboratory in four different conditions: (a) audio samples only, (b) original audio-visual samples, (c) video samples only, and (d) mixed audio-visual samples. The general results of this experiment showed a significant difference between the investigated conditions, but not for all the investigated samples. There was a significant improvement in comfort assessment when visual information was added (in only three out of 7 cases), when conditions (a) and (b) were compared. On the other hand, the results show that the comfort assessment of audio-visual samples could be changed by manipulating the audio rather than the video part of the audio-visual sample. Finally, it seems, that people could differentiate audio-visual representations of a given place in the environment based rather of on the sound sources' compositions than on the sound level. Object identification is responsible for both landscape and soundscape grouping. Copyright © 2015. Published by Elsevier B.V.

  19. AudioRegent: Exploiting SimpleADL and SoX for Digital Audio Delivery

    Directory of Open Access Journals (Sweden)

    Nitin Arora

    2010-06-01

    Full Text Available AudioRegent is a command-line Python script currently being used by the University of Alabama Libraries’ Digital Services to create web-deliverable MP3s from regions within archival audio files. In conjunction with a small-footprint XML file called SimpleADL and SoX, an open-source command-line audio editor, AudioRegent batch processes archival audio files, allowing for one or many user-defined regions, particular to each audio file, to be extracted with additional audio processing in a transparent manner that leaves the archival audio file unaltered. Doing so has alleviated many of the tensions of cumbersome workflows, complicated documentation, preservation concerns, and reliance on expensive closed-source GUI audio applications.

  20. A Method to Detect AAC Audio Forgery

    Directory of Open Access Journals (Sweden)

    Qingzhong Liu

    2015-08-01

    Full Text Available Advanced Audio Coding (AAC, a standardized lossy compression scheme for digital audio, which was designed to be the successor of the MP3 format, generally achieves better sound quality than MP3 at similar bit rates. While AAC is also the default or standard audio format for many devices and AAC audio files may be presented as important digital evidences, the authentication of the audio files is highly needed but relatively missing. In this paper, we propose a scheme to expose tampered AAC audio streams that are encoded at the same encoding bit-rate. Specifically, we design a shift-recompression based method to retrieve the differential features between the re-encoded audio stream at each shifting and original audio stream, learning classifier is employed to recognize different patterns of differential features of the doctored forgery files and original (untouched audio files. Experimental results show that our approach is very promising and effective to detect the forgery of the same encoding bit-rate on AAC audio streams. Our study also shows that shift recompression-based differential analysis is very effective for detection of the MP3 forgery at the same bit rate.

  1. Audio-visual gender recognition

    Science.gov (United States)

    Liu, Ming; Xu, Xun; Huang, Thomas S.

    2007-11-01

    Combining different modalities for pattern recognition task is a very promising field. Basically, human always fuse information from different modalities to recognize object and perform inference, etc. Audio-Visual gender recognition is one of the most common task in human social communication. Human can identify the gender by facial appearance, by speech and also by body gait. Indeed, human gender recognition is a multi-modal data acquisition and processing procedure. However, computational multimodal gender recognition has not been extensively investigated in the literature. In this paper, speech and facial image are fused to perform a mutli-modal gender recognition for exploring the improvement of combining different modalities.

  2. Digital audio watermarking fundamentals, techniques and challenges

    CERN Document Server

    Xiang, Yong; Yan, Bin

    2017-01-01

    This book offers comprehensive coverage on the most important aspects of audio watermarking, from classic techniques to the latest advances, from commonly investigated topics to emerging research subdomains, and from the research and development achievements to date, to current limitations, challenges, and future directions. It also addresses key topics such as reversible audio watermarking, audio watermarking with encryption, and imperceptibility control methods. The book sets itself apart from the existing literature in three main ways. Firstly, it not only reviews classical categories of audio watermarking techniques, but also provides detailed descriptions, analysis and experimental results of the latest work in each category. Secondly, it highlights the emerging research topic of reversible audio watermarking, including recent research trends, unique features, and the potentials of this subdomain. Lastly, the joint consideration of audio watermarking and encryption is also reviewed. With the help of this...

  3. Modified BTC Algorithm for Audio Signal Coding

    Directory of Open Access Journals (Sweden)

    TOMIC, S.

    2016-11-01

    Full Text Available This paper describes modification of a well-known image coding algorithm, named Block Truncation Coding (BTC and its application in audio signal coding. BTC algorithm was originally designed for black and white image coding. Since black and white images and audio signals have different statistical characteristics, the application of this image coding algorithm to audio signal presents a novelty and a challenge. Several implementation modifications are described in this paper, while the original idea of the algorithm is preserved. The main modifications are performed in the area of signal quantization, by designing more adequate quantizers for audio signal processing. The result is a novel audio coding algorithm, whose performance is presented and analyzed in this research. The performance analysis indicates that this novel algorithm can be successfully applied in audio signal coding.

  4. Presence and the utility of audio spatialization

    DEFF Research Database (Denmark)

    Bormann, Karsten

    2005-01-01

    The primary concern of this paper is whether the utility of audio spatialization, as opposed to the fidelity of audio spatialization, impacts presence. An experiment is reported that investigates the presence-performance relationship by decoupling spatial audio fidelity (realism) from task...... performance by varying the spatial fidelity of the audio independently of its relevance to performance on the search task that subjects were to perform. This was achieved by having conditions in which subjects searched for a music-playing radio (an active sound source) and having conditions in which...... supplied only nonattenuated audio was detrimental to performance. Even so, this group of subjects consistently had the largest increase in presence scores over the baseline experiment. Further, the Witmer and Singer (1998) presence questionnaire was more sensitive to whether the audio source was active...

  5. Making the Switch to Digital Audio

    Directory of Open Access Journals (Sweden)

    Shannon Gwin Mitchell

    2004-12-01

    Full Text Available In this article, the authors describe the process of converting from analog to digital audio data. They address the step-by-step decisions that they made in selecting hardware and software for recording and converting digital audio, issues of system integration, and cost considerations. The authors present a brief description of how digital audio is being used in their current research project and how it has enhanced the “quality” of their qualitative research.

  6. Video genre categorization and representation using audio-visual information

    Science.gov (United States)

    Ionescu, Bogdan; Seyerlehner, Klaus; Rasche, Christoph; Vertan, Constantin; Lambert, Patrick

    2012-04-01

    We propose an audio-visual approach to video genre classification using content descriptors that exploit audio, color, temporal, and contour information. Audio information is extracted at block-level, which has the advantage of capturing local temporal information. At the temporal structure level, we consider action content in relation to human perception. Color perception is quantified using statistics of color distribution, elementary hues, color properties, and relationships between colors. Further, we compute statistics of contour geometry and relationships. The main contribution of our work lies in harnessing the descriptive power of the combination of these descriptors in genre classification. Validation was carried out on over 91 h of video footage encompassing 7 common video genres, yielding average precision and recall ratios of 87% to 100% and 77% to 100%, respectively, and an overall average correct classification of up to 97%. Also, experimental comparison as part of the MediaEval 2011 benchmarking campaign demonstrated the efficiency of the proposed audio-visual descriptors over other existing approaches. Finally, we discuss a 3-D video browsing platform that displays movies using feature-based coordinates and thus regroups them according to genre.

  7. Three-Dimensional Audio Client Library

    Science.gov (United States)

    Rizzi, Stephen A.

    2005-01-01

    The Three-Dimensional Audio Client Library (3DAudio library) is a group of software routines written to facilitate development of both stand-alone (audio only) and immersive virtual-reality application programs that utilize three-dimensional audio displays. The library is intended to enable the development of three-dimensional audio client application programs by use of a code base common to multiple audio server computers. The 3DAudio library calls vendor-specific audio client libraries and currently supports the AuSIM Gold-Server and Lake Huron audio servers. 3DAudio library routines contain common functions for (1) initiation and termination of a client/audio server session, (2) configuration-file input, (3) positioning functions, (4) coordinate transformations, (5) audio transport functions, (6) rendering functions, (7) debugging functions, and (8) event-list-sequencing functions. The 3DAudio software is written in the C++ programming language and currently operates under the Linux, IRIX, and Windows operating systems.

  8. The Photovolatic Power Converter: A Technology Readiness Assessment

    Science.gov (United States)

    2005-06-01

    PVPC incorporates two critical technologies – Maximum Power Point Tracking ( MPPT ) and Switch Mode Power Conversion (SMPC). Panel Voltage (V) 12 33...a load that exceeds its voltage window, such as an 18V battery. Below in Figure 3 is a schematic of a standard MPPT circuit...to optimize the power output of a 9V solar panel and can increase that Voltage up to about 16V. Therefore, as currently produced, one size does not

  9. A Model of Distraction in an Audio-on-Audio Interference Situation with Music Program Material

    DEFF Research Database (Denmark)

    Francombe, J.; Mason, R.; Dewhirst, M.

    2015-01-01

    by a qualitative analysis of subject responses. Distraction ratings were collected for one hundred randomly created audio-on-audio interference situations with music target and interferer programs. The selected features were related to the overall loudness, loudness ratio, perceptual evaluation of audio source...

  10. Distortion Estimation in Compressed Music Using Only Audio Fingerprints

    NARCIS (Netherlands)

    Doets, P.J.O.; Lagendijk, R.L.

    2008-01-01

    An audio fingerprint is a compact yet very robust representation of the perceptually relevant parts of an audio signal. It can be used for content-based audio identification, even when the audio is severely distorted. Audio compression changes the fingerprint slightly. We show that these small

  11. Comparison of three different Modulators for Power Converters with Respect to EMI Optimization

    DEFF Research Database (Denmark)

    Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael Andreas E.

    2008-01-01

    Switch-mode Power Converters are well known for emissions in the band of electromagnetic interference (EMI) interest. The spectrum shape depends on the type of modulator and its purpose. This paper gives design guidelines to choose the optimum topology depending on requirements of different...

  12. High average power Q-switched 1314 nm two-crystal Nd:YLF laser

    CSIR Research Space (South Africa)

    Botha, RC

    2015-02-01

    Full Text Available A 1314 nm two-crystal Nd:YLF laser was designed and operated in both CW and actively Q-switched modes. Maximum CW output of 26.5 W resulted from 125 W of combined incident pump power. Active Q-switching was obtained by inserting a Brewster...

  13. Presence and the utility of audio spatialization

    DEFF Research Database (Denmark)

    Bormann, Karsten

    2005-01-01

    or not, while the presence questionnaire used by Slater and coworkers (see Tromp et al., 1998) was more sensitive to whether audio was fully spatialized or not. Finally, having the sound source active positively impacts the assessment of the audio while negatively impacting subjects' assessment...

  14. Audio Classification from Time-Frequency Texture

    OpenAIRE

    Yu, Guoshen; Slotine, Jean-Jacques

    2008-01-01

    Time-frequency representations of audio signals often resemble texture images. This paper derives a simple audio classification algorithm based on treating sound spectrograms as texture images. The algorithm is inspired by an earlier visual classification scheme particularly efficient at classifying textures. While solely based on time-frequency texture features, the algorithm achieves surprisingly good performance in musical instrument classification experiments.

  15. Synchronization and comparison of Lifelog audio recordings

    DEFF Research Database (Denmark)

    Nielsen, Andreas Brinch; Hansen, Lars Kai

    2008-01-01

    We investigate concurrent ‘Lifelog’ audio recordings to locate segments from the same environment. We compare two techniques earlier proposed for pattern recognition in extended audio recordings, namely cross-correlation and a fingerprinting technique. If successful, such alignment can be used...

  16. Prediction of perceptual audio reproduction characteristics

    DEFF Research Database (Denmark)

    Volk, Christer Peter

    affects perception. In this project a number of audio metrics are presented, which describes perceptual characteristics in terms of properties of the physical acoustical output of headphones and loudspeakers. The audio metrics relies on perceptual models for estimations of the how these acoustical outputs...

  17. A listening test system for automotive audio

    DEFF Research Database (Denmark)

    Christensen, Flemming; Geoff, Martin; Minnaar, Pauli

    2005-01-01

    This paper describes a system for simulating automotive audio through headphones for the purposes of conducting listening experiments in the laboratory. The system is based on binaural technology and consists of a component for reproducing the sound of the audio system itself and a component...

  18. Digital signal processor for silicon audio playback devices; Silicon audio saisei kikiyo digital signal processor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The digital audio signal processor (DSP) TC9446F series has been developed silicon audio playback devices with a memory medium of, e.g., flash memory, DVD players, and AV devices, e.g., TV sets. It corresponds to AAC (advanced audio coding) (2ch) and MP3 (MPEG1 Layer3), as the audio compressing techniques being used for transmitting music through an internet. It also corresponds to compressed types, e.g., Dolby Digital, DTS (digital theater system) and MPEG2 audio, being adopted for, e.g., DVDs. It can carry a built-in audio signal processing program, e.g., Dolby ProLogic, equalizer, sound field controlling, and 3D sound. TC9446XB has been lined up anew. It adopts an FBGA (fine pitch ball grid array) package for portable audio devices. (translated by NEDO)

  19. Extraction of ions and electrons from audio frequency plasma source

    Directory of Open Access Journals (Sweden)

    N. A. Haleem

    2016-09-01

    Full Text Available Herein, the extraction of high ion / electron current from an audio frequency (AF nitrogen gas discharge (10 – 100 kHz is studied and investigated. This system is featured by its small size (L= 20 cm and inner diameter = 3.4 cm and its capacitive discharge electrodes inside the tube and its high discharge pressure ∼ 0.3 Torr, without the need of high vacuum system or magnetic fields. The extraction system of ion/electron current from the plasma is a very simple electrode that allows self-beam focusing by adjusting its position from the source exit. The working discharge conditions were applied at a frequency from 10 to 100 kHz, power from 50 – 500 W and the gap distance between the plasma meniscus surface and the extractor electrode extending from 3 to 13 mm. The extracted ion/ electron current is found mainly dependent on the discharge power, the extraction gap width and the frequency of the audio supply. SIMION 3D program version 7.0 package is used to generate a simulation of ion trajectories as a reference to compare and to optimize the experimental extraction beam from the present audio frequency plasma source using identical operational conditions. The focal point as well the beam diameter at the collector area is deduced. The simulations showed a respectable agreement with the experimental results all together provide the optimizing basis of the extraction electrode construction and its parameters for beam production.

  20. Estimation of inhalation flow profile using audio-based methods to assess inhaler medication adherence.

    Science.gov (United States)

    Taylor, Terence E; Lacalle Muls, Helena; Costello, Richard W; Reilly, Richard B

    2018-01-01

    Asthma and chronic obstructive pulmonary disease (COPD) patients are required to inhale forcefully and deeply to receive medication when using a dry powder inhaler (DPI). There is a clinical need to objectively monitor the inhalation flow profile of DPIs in order to remotely monitor patient inhalation technique. Audio-based methods have been previously employed to accurately estimate flow parameters such as the peak inspiratory flow rate of inhalations, however, these methods required multiple calibration inhalation audio recordings. In this study, an audio-based method is presented that accurately estimates inhalation flow profile using only one calibration inhalation audio recording. Twenty healthy participants were asked to perform 15 inhalations through a placebo Ellipta™ DPI at a range of inspiratory flow rates. Inhalation flow signals were recorded using a pneumotachograph spirometer while inhalation audio signals were recorded simultaneously using the Inhaler Compliance Assessment device attached to the inhaler. The acoustic (amplitude) envelope was estimated from each inhalation audio signal. Using only one recording, linear and power law regression models were employed to determine which model best described the relationship between the inhalation acoustic envelope and flow signal. Each model was then employed to estimate the flow signals of the remaining 14 inhalation audio recordings. This process repeated until each of the 15 recordings were employed to calibrate single models while testing on the remaining 14 recordings. It was observed that power law models generated the highest average flow estimation accuracy across all participants (90.89±0.9% for power law models and 76.63±2.38% for linear models). The method also generated sufficient accuracy in estimating inhalation parameters such as peak inspiratory flow rate and inspiratory capacity within the presence of noise. Estimating inhaler inhalation flow profiles using audio based methods may be

  1. High-Fidelity Piezoelectric Audio Device

    Science.gov (United States)

    Woodward, Stanley E.; Fox, Robert L.; Bryant, Robert G.

    2003-01-01

    ModalMax is a very innovative means of harnessing the vibration of a piezoelectric actuator to produce an energy efficient low-profile device with high-bandwidth high-fidelity audio response. The piezoelectric audio device outperforms many commercially available speakers made using speaker cones. The piezoelectric device weighs substantially less (4 g) than the speaker cones which use magnets (10 g). ModalMax devices have extreme fabrication simplicity. The entire audio device is fabricated by lamination. The simplicity of the design lends itself to lower cost. The piezoelectric audio device can be used without its acoustic chambers and thereby resulting in a very low thickness of 0.023 in. (0.58 mm). The piezoelectric audio device can be completely encapsulated, which makes it very attractive for use in wet environments. Encapsulation does not significantly alter the audio response. Its small size (see Figure 1) is applicable to many consumer electronic products, such as pagers, portable radios, headphones, laptop computers, computer monitors, toys, and electronic games. The audio device can also be used in automobile or aircraft sound systems.

  2. Implementing Audio-CASI on Windows’ Platforms

    Science.gov (United States)

    Cooley, Philip C.; Turner, Charles F.

    2011-01-01

    Audio computer-assisted self interviewing (Audio-CASI) technologies have recently been shown to provide important and sometimes dramatic improvements in the quality of survey measurements. This is particularly true for measurements requiring respondents to divulge highly sensitive information such as their sexual, drug use, or other sensitive behaviors. However, DOS-based Audio-CASI systems that were designed and adopted in the early 1990s have important limitations. Most salient is the poor control they provide for manipulating the video presentation of survey questions. This article reports our experiences adapting Audio-CASI to Microsoft Windows 3.1 and Windows 95 platforms. Overall, our Windows-based system provided the desired control over video presentation and afforded other advantages including compatibility with a much wider array of audio devices than our DOS-based Audio-CASI technologies. These advantages came at the cost of increased system requirements --including the need for both more RAM and larger hard disks. While these costs will be an issue for organizations converting large inventories of PCS to Windows Audio-CASI today, this will not be a serious constraint for organizations and individuals with small inventories of machines to upgrade or those purchasing new machines today. PMID:22081743

  3. Phase synchronized quasiperiodicity in power electronic inverter systems

    DEFF Research Database (Denmark)

    Zhusubaliyev, Zhanybai T.; Mosekilde, Erik; Andriyanov, Alexey I.

    2014-01-01

    The development of switch-mode operated power electronic converter systems has provided a broad range of new effective approaches to the conversion of electric power. In this paper we describe the transitions from regular periodic operation to quasiperiodicity and high-periodic resonance behavior...... findings are verified through comparison with an experimental inverter system. The results shed light on the transitions to quasiperiodicity and to various forms of three-frequency dynamics in non-smooth systems....

  4. Real-Time Audio Processing on the T-CREST Multicore Platform

    DEFF Research Database (Denmark)

    Ausin, Daniel Sanz; Pezzarossa, Luca; Schoeberl, Martin

    2017-01-01

    of the audio signal. This paper presents a real-time multicore audio processing system based on the T-CREST platform. T-CREST is a time-predictable multicore processor for real-time embedded systems. Multiple audio effect tasks have been implemented, which can be connected together in different configurations...... forming sequential and parallel effect chains, and using a network-onchip for intercommunication between processors. The evaluation of the system shows that real-time processing of multiple effect configurations is possible, and that the estimation and control of latency ensures real-time behavior.......Multicore platforms are nowadays widely used for audio processing applications, due to the improvement of computational power that they provide. However, some of these systems are not optimized for temporally constrained environments, which often leads to an undesired increase in the latency...

  5. Near-field Localization of Audio

    DEFF Research Database (Denmark)

    Jensen, Jesper Rindom; Christensen, Mads Græsbøll

    2014-01-01

    Localization of audio sources using microphone arrays has been an important research problem for more than two decades. Many traditional methods for solving the problem are based on a two-stage procedure: first, information about the audio source, such as time differences-of-arrival (TDOAs......) and gain ratios-of-arrival (GROAs) between microphones is estimated, and, second, this knowledge is used to localize the audio source. These methods often have a low computational complexity, but this comes at the cost of a limited estimation accuracy. Therefore, we propose a new localization approach...

  6. Musical Audio Synthesis Using Autoencoding Neural Nets

    OpenAIRE

    Sarroff, Andy; Casey, Michael A.

    2014-01-01

    With an optimal network topology and tuning of hyperpa-\\ud rameters, artificial neural networks (ANNs) may be trained\\ud to learn a mapping from low level audio features to one\\ud or more higher-level representations. Such artificial neu-\\ud ral networks are commonly used in classification and re-\\ud gression settings to perform arbitrary tasks. In this work\\ud we suggest repurposing autoencoding neural networks as\\ud musical audio synthesizers. We offer an interactive musi-\\ud cal audio synt...

  7. Audio-Visual Classification of Sports Types

    DEFF Research Database (Denmark)

    Gade, Rikke; Abou-Zleikha, Mohamed; Christensen, Mads Græsbøll

    2015-01-01

    In this work we propose a method for classification of sports types from combined audio and visual features ex- tracted from thermal video. From audio Mel Frequency Cepstral Coefficients (MFCC) are extracted, and PCA are applied to reduce the feature space to 10 dimensions. From the visual modality...... short trajectories are constructed to rep- resent the motion of players. From these, four motion fea- tures are extracted and combined directly with audio fea- tures for classification. A k-nearest neighbour classifier is applied for classification of 180 1-minute video sequences from three sports types...

  8. 3D Audio Acquisition and Reproduction Systems

    OpenAIRE

    Evrard, Marc; André, Cédric; Embrechts, Jean-Jacques; Verly, Jacques

    2011-01-01

    This presentation introduces two different research projects dealing with 3D audio for 3D-stereoscopic movies. The first project “3D audio acquisition for real time applications” studies the best method for acquiring a full 3D audio soundscape on location and for processing it in real-time for further reproduction. The second project “Adding 3D sound to 3D cinema” is aimed towards the study of reproducing a 3D soundscape consistent with the visual content of a 3D-stereoscopic movie. ...

  9. Interactive Audio Visual Learning: An Overview

    Science.gov (United States)

    Reich, Steven D.

    1984-01-01

    Interactive AudioVisual Learning (IAVL) is a dynamic branch of computer-assisted instruction that adds the dimensions of sight and sound to programmed learning. The power of audiovisual media to present complex concepts is coupled with the capabilities of a computer to analyze a learner's response to questions and then to direct the flow of information. The development of lessons in this format usually requires the input of content specialists, instructional designers, audiovisual media experts, and programmers. The IAVL format appears to be well accepted by learners and has been shown to be an efficient means of teaching. No standards for hardware, software, or presentation of material have been set, so efforts in the area of IAVL remain scattered. Several groups are actively working in the field of medically related subjects, but the major emphasis for most production teams is on corporate training. The commercial sector will probably be responsible for standardizing software and hardware, but lesson content for medical professionals will require medical educators. Since IAVL lessons are so different from standard lecture formats, more medical educators will have to be introduced to IAVL in order to create enough interest to get IAVL moved into the medical curriculum. The developmental efforts of those involved in IAVL productions for the education of medical professionals are important to the ultimate acceptance of the IAVL format.

  10. High quality scalable audio codec

    Science.gov (United States)

    Kim, Miyoung; Oh, Eunmi; Kim, JungHoe

    2007-09-01

    The MPEG-4 BSAC (Bit Sliced Arithmetic Coding) is a fine-grain scalable codec with layered structure which consists of a single base-layer and several enhancement layers. The scalable functionality allows us to decode the subsets of a full bitstream and to deliver audio contents adaptively under conditions of heterogeneous network and devices, and user interaction. This bitrate scalability can be provided at the cost of high frequency components. It means that the decoded output of BSAC sounds muffled as the transmitted layers become less and less due to deprived conditions of network and devices. The goal of the proposed technology is to compensate the missing high frequency components, while maintaining the fine grain scalability of BSAC. This paper describes the integration of SBR (Spectral Bandwidth Replication) tool to existing MPEG-4 BSAC. Listening test results show that the sound quality of BSAC is improved when the full bitstream is truncated for lower bitrates, and this quality is comparable to that of BSAC using SBR tool without truncation at the same bitrate.

  11. Web Audio/Video Streaming Tool

    Science.gov (United States)

    Guruvadoo, Eranna K.

    2003-01-01

    In order to promote NASA-wide educational outreach program to educate and inform the public of space exploration, NASA, at Kennedy Space Center, is seeking efficient ways to add more contents to the web by streaming audio/video files. This project proposes a high level overview of a framework for the creation, management, and scheduling of audio/video assets over the web. To support short-term goals, the prototype of a web-based tool is designed and demonstrated to automate the process of streaming audio/video files. The tool provides web-enabled users interfaces to manage video assets, create publishable schedules of video assets for streaming, and schedule the streaming events. These operations are performed on user-defined and system-derived metadata of audio/video assets stored in a relational database while the assets reside on separate repository. The prototype tool is designed using ColdFusion 5.0.

  12. Virtual Microphones for Multichannel Audio Resynthesis

    Directory of Open Access Journals (Sweden)

    Athanasios Mouchtaris

    2003-09-01

    Full Text Available Multichannel audio offers significant advantages for music reproduction, including the ability to provide better localization and envelopment, as well as reduced imaging distortion. On the other hand, multichannel audio is a demanding media type in terms of transmission requirements. Often, bandwidth limitations prohibit transmission of multiple audio channels. In such cases, an alternative is to transmit only one or two reference channels and recreate the rest of the channels at the receiving end. Here, we propose a system capable of synthesizing the required signals from a smaller set of signals recorded in a particular venue. These synthesized “virtual” microphone signals can be used to produce multichannel recordings that accurately capture the acoustics of that venue. Applications of the proposed system include transmission of multichannel audio over the current Internet infrastructure and, as an extension of the methods proposed here, remastering existing monophonic and stereophonic recordings for multichannel rendering.

  13. EVALUASI KEPUASAN PENGGUNA TERHADAP APLIKASI AUDIO BOOKS

    Directory of Open Access Journals (Sweden)

    Raditya Maulana Anuraga

    2017-02-01

    Full Text Available Listeno is the first application audio books in Indonesia so that the users can get the book in audio form like listen to music, Listeno have problems in a feature request Listeno offline mode that have not been released, a security problem mp3 files that must be considered, and the target Listeno not yet reached 100,000 active users. This research has the objective to evaluate user satisfaction to Audio Books with research method approach, Nielsen. The analysis in this study using Importance Performance Analysis (IPA is combined with the index of User Satisfaction (IKP based on the indicators used are: Benefit (Usefulness, Utility (Utility, Usability (Usability, easy to understand (Learnability, Efficient (efficiency , Easy to remember (Memorability, Error (Error, and satisfaction (satisfaction. The results showed Applications User Satisfaction Audio books are quite satisfied with the results of the calculation IKP 69.58%..

  14. CERN automatic audio-conference service

    CERN Document Server

    Sierra Moral, R

    2010-01-01

    Scientists from all over the world need to collaborate with CERN on a daily basis. They must be able to communicate effectively on their joint projects at any time; as a result telephone conferences have become indispensable and widely used. Managed by 6 operators, CERN already has more than 20000 hours and 5700 audio-conferences per year. However, the traditional telephone based audio-conference system needed to be modernized in three ways. Firstly, to provide the participants with more autonomy in the organization of their conferences; secondly, to eliminate the constraints of manual intervention by operators; and thirdly, to integrate the audio-conferences into a collaborative working framework. The large number, and hence cost, of the conferences prohibited externalization and so the CERN telecommunications team drew up a specification to implement a new system. It was decided to use a new commercial collaborative audio-conference solution based on the SIP protocol. The system was tested as the first Euro...

  15. Augmenting Environmental Interaction in Audio Feedback Systems

    Directory of Open Access Journals (Sweden)

    Seunghun Kim

    2016-04-01

    Full Text Available Audio feedback is defined as a positive feedback of acoustic signals where an audio input and output form a loop, and may be utilized artistically. This article presents new context-based controls over audio feedback, leading to the generation of desired sonic behaviors by enriching the influence of existing acoustic information such as room response and ambient noise. This ecological approach to audio feedback emphasizes mutual sonic interaction between signal processing and the acoustic environment. Mappings from analyses of the received signal to signal-processing parameters are designed to emphasize this specificity as an aesthetic goal. Our feedback system presents four types of mappings: approximate analyses of room reverberation to tempo-scale characteristics, ambient noise to amplitude and two different approximations of resonances to timbre. These mappings are validated computationally and evaluated experimentally in different acoustic conditions.

  16. Spatial audio reproduction with primary ambient extraction

    CERN Document Server

    He, JianJun

    2017-01-01

    This book first introduces the background of spatial audio reproduction, with different types of audio content and for different types of playback systems. A literature study on the classical and emerging Primary Ambient Extraction (PAE) techniques is presented. The emerging techniques aim to improve the extraction performance and also enhance the robustness of PAE approaches in dealing with more complex signals encountered in practice. The in-depth theoretical study helps readers to understand the rationales behind these approaches. Extensive objective and subjective experiments validate the feasibility of applying PAE in spatial audio reproduction systems. These experimental results, together with some representative audio examples and MATLAB codes of the key algorithms, illustrate clearly the differences among various approaches and also help readers gain insights on selecting different approaches for different applications.

  17. CERN automatic audio-conference service

    CERN Multimedia

    Sierra Moral, R

    2009-01-01

    Scientists from all over the world need to collaborate with CERN on a daily basis. They must be able to communicate effectively on their joint projects at any time; as a result telephone conferences have become indispensable and widely used. Managed by 6 operators, CERN already has more than 20000 hours and 5700 audio-conferences per year. However, the traditional telephone based audio-conference system needed to be modernized in three ways. Firstly, to provide the participants with more autonomy in the organization of their conferences; secondly, to eliminate the constraints of manual intervention by operators; and thirdly, to integrate the audio-conferences into a collaborative working framework. The large number, and hence cost, of the conferences prohibited externalization and so the CERN telecommunications team drew up a specification to implement a new system. It was decided to use a new commercial collaborative audio-conference solution based on the SIP protocol. The system was tested as the first Euro...

  18. Parametric time-frequency domain spatial audio

    CERN Document Server

    Delikaris-Manias, Symeon; Politis, Archontis

    2018-01-01

    This book provides readers with the principles and best practices in spatial audio signal processing. It describes how sound fields and their perceptual attributes are captured and analyzed within the time-frequency domain, how essential representation parameters are coded, and how such signals are efficiently reproduced for practical applications. The book is split into four parts starting with an overview of the fundamentals. It then goes on to explain the reproduction of spatial sound before offering an examination of signal-dependent spatial filtering. The book finishes with coverage of both current and future applications and the direction that spatial audio research is heading in. Parametric Time-frequency Domain Spatial Audio focuses on applications in entertainment audio, including music, home cinema, and gaming--covering the capturing and reproduction of spatial sound as well as its generation, transduction, representation, transmission, and perception. This book will teach readers the tools needed...

  19. Audio production principles practical studio applications

    CERN Document Server

    Elmosnino, Stephane

    2018-01-01

    A new and fully practical guide to all of the key topics in audio production, this book covers the entire workflow from pre-production, to recording all kinds of instruments, to mixing theories and tools, and finally to mastering.

  20. Design of an audio advertisement dataset

    Science.gov (United States)

    Fu, Yutao; Liu, Jihong; Zhang, Qi; Geng, Yuting

    2015-12-01

    Since more and more advertisements swarm into radios, it is necessary to establish an audio advertising dataset which could be used to analyze and classify the advertisement. A method of how to establish a complete audio advertising dataset is presented in this paper. The dataset is divided into four different kinds of advertisements. Each advertisement's sample is given in *.wav file format, and annotated with a txt file which contains its file name, sampling frequency, channel number, broadcasting time and its class. The classifying rationality of the advertisements in this dataset is proved by clustering the different advertisements based on Principal Component Analysis (PCA). The experimental results show that this audio advertisement dataset offers a reliable set of samples for correlative audio advertisement experimental studies.

  1. Watermarking-Based Digital Audio Data Authentication

    Directory of Open Access Journals (Sweden)

    Jana Dittmann

    2003-09-01

    Full Text Available Digital watermarking has become an accepted technology for enabling multimedia protection schemes. While most efforts concentrate on user authentication, recently interest in data authentication to ensure data integrity has been increasing. Existing concepts address mainly image data. Depending on the necessary security level and the sensitivity to detect changes in the media, we differentiate between fragile, semifragile, and content-fragile watermarking approaches for media authentication. Furthermore, invertible watermarking schemes exist while each bit change can be recognized by the watermark which can be extracted and the original data can be reproduced for high-security applications. Later approaches can be extended with cryptographic approaches like digital signatures. As we see from the literature, only few audio approaches exist and the audio domain requires additional strategies for time flow protection and resynchronization. To allow different security levels, we have to identify relevant audio features that can be used to determine content manipulations. Furthermore, in the field of invertible schemes, there are a bunch of publications for image and video data but no approaches for digital audio to ensure data authentication for high-security applications. In this paper, we introduce and evaluate two watermarking algorithms for digital audio data, addressing content integrity protection. In our first approach, we discuss possible features for a content-fragile watermarking scheme to allow several postproduction modifications. The second approach is designed for high-security applications to detect each bit change and reconstruct the original audio by introducing an invertible audio watermarking concept. Based on the invertible audio scheme, we combine digital signature schemes and digital watermarking to provide a public verifiable data authentication and a reproduction of the original, protected with a secret key.

  2. Audio Technology and Mobile Human Computer Interaction

    DEFF Research Database (Denmark)

    Chamberlain, Alan; Bødker, Mads; Hazzard, Adrian

    2017-01-01

    Audio-based mobile technology is opening up a range of new interactive possibilities. This paper brings some of those possibilities to light by offering a range of perspectives based in this area. It is not only the technical systems that are developing, but novel approaches to the design...... and understanding of audio-based mobile systems are evolving to offer new perspectives on interaction and design and support such systems to be applied in areas, such as the humanities....

  3. Audio Description as a Pedagogical Tool

    OpenAIRE

    Georgina Kleege; Scott Wallin

    2015-01-01

    Audio description is the process of translating visual information into words for people who are blind or have low vision. Typically such description has focused on films, museum exhibitions, images and video on the internet, and live theater. Because it allows people with visual impairments to experience a variety of cultural and educational texts that would otherwise be inaccessible, audio description is a mandated aspect of disability inclusion, although it remains markedly underdeveloped ...

  4. Audio description as an accessibility enhancer

    OpenAIRE

    Martins, Cláudia Susana Nunes

    2012-01-01

    Audio description for the blind and visually-impaired has been around since people have described what is seen. Throughout time, it has evolved and developed in different contexts, starting with daily life, moving into the cinema and television, then across other performing arts, museums and galleries, historical sites and public places. Audio description is above all an issue of accessibility and of providing visually-impaired people with the same rights to have access to culture, e...

  5. A 65-nm low-noise low-cost ΣΔ modulator for audio applications

    Science.gov (United States)

    Guo, Liang; Lu, Liao; Hao, Luo; Xiaopeng, Liu; Xiaoxia, Han; Yan, Han

    2012-02-01

    This paper introduces a low-noise low-cost ΣΔ modulator for digital audio analog-to-digital conversion. By adopting a low-noise large-output swing operation amplifier, not only is the flicker noise greatly inhibited, but also the power consumption is reduced. Also the area cost is relatively small. The modulator was implemented in a SMIC standard 65-nm CMOS process. Measurement results show it can achieve 96 dB peak signal-to-noise plus distortion ratio (SNDR) and 105 dB dynamic range (DR) over the 22.05-kHz audio band and occupies 0.16 mm2. The power consumption of the proposed modulator is 4.9 mW from a 2.5 V power supply, which is suitable for high-performance, low-cost audio codec applications.

  6. The Effect Of 3D Audio And Other Audio Techniques On Virtual Reality Experience.

    Science.gov (United States)

    Brinkman, Willem-Paul; Hoekstra, Allart R D; van Egmond, René

    2015-01-01

    Three studies were conducted to examine the effect of audio on people's experience in a virtual world. The first study showed that people could distinguish between mono, stereo, Dolby surround and 3D audio of a wasp. The second study found significant effects for audio techniques on people's self-reported anxiety, presence, and spatial perception. The third study found that adding sound to a visual virtual world had a significant effect on people's experience (including heart rate), while it found no difference in experience between stereo and 3D audio.

  7. PENGGUNAAN MEDIA AUDIO DALAM PEMBELAJARAN STENOGRAFI

    Directory of Open Access Journals (Sweden)

    S Martono

    2011-06-01

    Full Text Available The objective this study is to know the effectivenes of using audio media in stenografi typing learning. The population  of this research was 30 students that divided into two groups; experimental and controlled group consisted of 15 students. Based on the first score in stenografi subject that the two groups have the same abillity but they were given different treatment. For experimental group, they got a treatment of audio media whereas the controlled group didn’t use audio media. The technique of collecting data were documentation technique and experimental tecnique. The instrument was stenografi speed typing. The final result showed that the using of audio media was more effective and can improve the study result better than controlled group. This result was expected to  give significance for the stenografi teachers to apply audio media in learning and input for the students that stenografi was not a memorizing subject but it was a skill subject that must be trained by joining the lesson. Thus, people can use stenografi typing to record each talk. Keywords: Learning, Audio Media, Stenografi

  8. PENGGUNAAN MEDIA AUDIO DALAM PEMBELAJARAN STENOGRAFI

    Directory of Open Access Journals (Sweden)

    S Martono

    2007-06-01

    Full Text Available The objective this study is to know the effectivenes of using audio media in stenografi typing learning. The population  of this research was 30 students that divided into two groups; experimental and controlled group consisted of 15 students. Based on the first score in stenografi subject that the two groups have the same abillity but they were given different treatment. For experimental group, they got a treatment of audio media whereas the controlled group didn’t use audio media. The technique of collecting data were documentation technique and experimental tecnique. The instrument was stenografi speed typing. The final result showed that the using of audio media was more effective and can improve the study result better than controlled group. This result was expected to  give significance for the stenografi teachers to apply audio media in learning and input for the students that stenografi was not a memorizing subject but it was a skill subject that must be trained by joining the lesson. Thus, people can use stenografi typing to record each talk. Keywords: Learning, Audio Media, Stenografi

  9. The Audio Description as a Physics Teaching Tool

    Science.gov (United States)

    Cozendey, Sabrina; Costa, Maria da Piedade

    2016-01-01

    This study analyses the use of audio description in teaching physics concepts, aiming to determine the variables that influence the understanding of the concept. One education resource was audio described. For make the audio description the screen was freezing. The video with and without audio description should be presented to students, so that…

  10. Attitude of medical students towards the use of audio visual aids during didactic lectures in pharmacology in a medical college of central India

    OpenAIRE

    Mehul Agrawal; Rajanish Kumar Sankdia

    2016-01-01

    Background: Students favour teaching methods employing audio visual aids over didactic lectures not using these aids. However, the optimum use of audio visual aids is essential for deriving their benefits. During a lecture, both the visual and auditory senses are used to absorb information. Different methods of lecture are and ndash; chalk and board, power point presentations (PPT) and mix of aids. This study was done to know the students' preference regarding the various audio visual aids, ...

  11. StirMark Benchmark: audio watermarking attacks based on lossy compression

    Science.gov (United States)

    Steinebach, Martin; Lang, Andreas; Dittmann, Jana

    2002-04-01

    StirMark Benchmark is a well-known evaluation tool for watermarking robustness. Additional attacks are added to it continuously. To enable application based evaluation, in our paper we address attacks against audio watermarks based on lossy audio compression algorithms to be included in the test environment. We discuss the effect of different lossy compression algorithms like MPEG-2 audio Layer 3, Ogg or VQF on a selection of audio test data. Our focus is on changes regarding the basic characteristics of the audio data like spectrum or average power and on removal of embedded watermarks. Furthermore we compare results of different watermarking algorithms and show that lossy compression is still a challenge for most of them. There are two strategies for adding evaluation of robustness against lossy compression to StirMark Benchmark: (a) use of existing free compression algorithms (b) implementation of a generic lossy compression simulation. We discuss how such a model can be implemented based on the results of our tests. This method is less complex, as no real psycho acoustic model has to be applied. Our model can be used for audio watermarking evaluation of numerous application fields. As an example, we describe its importance for e-commerce applications with watermarking security.

  12. Implementation of Audio signal by using wavelet transform

    OpenAIRE

    Chakresh kumar,; Chandra Shekhar; Ashu Soni; Bindu Thakral

    2010-01-01

    Audio coding is the technology to represent audio in digital form with as few bits as possible while maintaining the intelligibility and quality required for particular application. Interest in audio coding is motivated by the evolution to digital communications and the requirement to minimize bit rate, and hence conserve bandwidth. There is always a tradeoff between compression ratio and maintaining the delivered audio quality and intelligibility. Audio coding is widely used in application s...

  13. Audio Source Localization using a Network of Embedded Devices

    Directory of Open Access Journals (Sweden)

    FRANGU, L.

    2010-05-01

    Full Text Available In this paper, a problem of audio source localization is solved, using a network of embedded devices. The intensive computing procedures (such as the crosscorrelation functions are performed by the embedded devices, which have enough speed and memory for this task. A central computer computes the position in a fast procedure, using the data transmitted by the network nodes, and plays the role of operator interface. The paper also contains the description of the embedded devices, which are designed and manufactured by the authors. They prove to be suited for this kind of application, as they perform fast computation and require low power and small space for installing.

  14. Utilization of non-linear converters for audio amplification

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Birch, Thomas; Knott, Arnold

    2012-01-01

    Class D amplifiers fits the automotive demands quite well. The traditional buck-based amplifier has reduced both the cost and size of amplifiers. However the buck topology is not without its limitations. The maximum peak AC output voltage produced by the power stage is only equal the supply voltage....... The introduction of non-linear converters for audio amplification defeats this limitation. A Cuk converter, designed to deliver an AC peak output voltage twice the supply voltage, is presented in this paper. A 3V prototype has been developed to prove the concept. The prototype shows that it is possible to achieve...

  15. Audio Arduino - an ALSA (Advanced Linux Sound Architecture) audio driver for FTDI-based Arduinos

    DEFF Research Database (Denmark)

    Dimitrov, Smilen; Serafin, Stefania

    2011-01-01

    A contemporary PC user, typically expects a sound card to be a piece of hardware, that: can be manipulated by 'audio' software (most typically exemplified by 'media players'); and allows interfacing of the PC to audio reproduction and/or recording equipment. As such, a 'sound card' can be conside...

  16. Video equipment of tele dosimetry and audio

    International Nuclear Information System (INIS)

    Ojeda R, M.A.; Padilla C, I.

    2007-01-01

    To develop a work in an area with high radiation, it requires of a detailed knowledge of the surroundings work, a communication and effective vision, a near dosimetric control. In a work where the spaces variables and reduced accesses exist, noise that hinders the communication, defendant operative condition, radiation field and taking of decision, it is necessary to have tools that allow a total control of the environment to make opportune and effective decisions, there where the task is developed. Under this elementary concept, it was developed in the Laguna Verde Central a project that it allowed a mechanism, interactive of control in spaces complex; to see, to hear, to speak, to measure. This concept takes to the creation of an equipped system with closed circuit of television, wireless communication systems, tele dosimetry wireless systems, VHS and DVD recording equipment, uninterrupted energy units. The system requires of an electric power socket, and the installation of two cables by CCTV camera. The system is mobilized by a person. He puts on in operation in 5 minutes using a verification list. The concept was developed in the project denominated VETA-1, (Video Equipment of Tele dosimetry and Audio). It is objective of this work to present before the society the development of the VETA-1 tool that conclude in their first prototype in May of the present year. The VETA-1 project arises by a necessity of optimizing dose, it is an ALARA tool, with a countless applications, like it was proven in the 12 recharge stop of the Unit 1. The VETA-1 project integrate a recording system, with the primary end of analyzing in the place where the task is developed the details for an effective and opportune decision, but the resulting information is of utility for the personnel's training and the planning of future works. The VETA-1 system is an ALARA tool of quick response control. (Author)

  17. Audio stream classification for multimedia database search

    Science.gov (United States)

    Artese, M.; Bianco, S.; Gagliardi, I.; Gasparini, F.

    2013-03-01

    Search and retrieval of huge archives of Multimedia data is a challenging task. A classification step is often used to reduce the number of entries on which to perform the subsequent search. In particular, when new entries of the database are continuously added, a fast classification based on simple threshold evaluation is desirable. In this work we present a CART-based (Classification And Regression Tree [1]) classification framework for audio streams belonging to multimedia databases. The database considered is the Archive of Ethnography and Social History (AESS) [2], which is mainly composed of popular songs and other audio records describing the popular traditions handed down generation by generation, such as traditional fairs, and customs. The peculiarities of this database are that it is continuously updated; the audio recordings are acquired in unconstrained environment; and for the non-expert human user is difficult to create the ground truth labels. In our experiments, half of all the available audio files have been randomly extracted and used as training set. The remaining ones have been used as test set. The classifier has been trained to distinguish among three different classes: speech, music, and song. All the audio files in the dataset have been previously manually labeled into the three classes above defined by domain experts.

  18. Hierarchical system for content-based audio classification and retrieval

    Science.gov (United States)

    Zhang, Tong; Kuo, C.-C. Jay

    1998-10-01

    A hierarchical system for audio classification and retrieval based on audio content analysis is presented in this paper. The system consists of three stages. The audio recordings are first classical and segmented into speech, music, several types of environmental sounds, and silence, based on morphological and statistical analysis of temporal curves of the energy function, the average zero-crossing rate, and the fundamental frequency of audio signals. The first stage is called the coarse-level audio classification and segmentation. Then, environmental sounds are classified into finer classes such as applause, rain, birds' sound, etc., which is called the fine-level audio classification. The second stage is based on time-frequency analysis of audio signals and the use of the hidden Markov model (HMM) for classification. In the third stage, the query-by-example audio retrieval is implemented where similar sounds can be found according to the input sample audio. The way of modeling audio features with the hidden Markov model, the procedures of audio classification and retrieval, and the experimental results are described. It is shown that, with the proposed new system, audio recordings can be automatically segmented and classified into basic types in real time with an accuracy higher than 90%. Examples of audio fine classification and audio retrieval with the proposed HMM-based method are also provided.

  19. Audio Description as a Pedagogical Tool

    Directory of Open Access Journals (Sweden)

    Georgina Kleege

    2015-05-01

    Full Text Available Audio description is the process of translating visual information into words for people who are blind or have low vision. Typically such description has focused on films, museum exhibitions, images and video on the internet, and live theater. Because it allows people with visual impairments to experience a variety of cultural and educational texts that would otherwise be inaccessible, audio description is a mandated aspect of disability inclusion, although it remains markedly underdeveloped and underutilized in our classrooms and in society in general. Along with increasing awareness of disability, audio description pushes students to practice close reading of visual material, deepen their analysis, and engage in critical discussions around the methodology, standards and values, language, and role of interpretation in a variety of academic disciplines. We outline a few pedagogical interventions that can be customized to different contexts to develop students' writing and critical thinking skills through guided description of visual material.

  20. Evaluation of Perceived Spatial Audio Quality

    Directory of Open Access Journals (Sweden)

    Jan Berg

    2006-04-01

    Full Text Available The increased use of audio applications capable of conveying enhanced spatial quality puts focus on how such a quality should be evaluated. Different approaches to evaluation of perceived quality are briefly discussed and a new technique is introduced. In a series of experiment, attributes were elicited from subjects, tested and subsequently used for derivation of evaluation scales that were feasible for subjective evaluation of the spatial quality of certain multichannel stimuli. The findings of these experiments led to the development of a novel method for evaluation of spatial audio in surround sound systems. Parts of the method were subsequently implemented in the OPAQUE software prototype designed to facilitate the elicitation process. The prototype was successfully tested in a pilot experiment. The experiments show that attribute scales derived from subjects' personal constructs are functional for evaluation of perceived spatial audio quality. Finally, conclusions on the importance of spatial quality evaluation of new applications are made.

  1. Frequency Hopping Method for Audio Watermarking

    Directory of Open Access Journals (Sweden)

    A. Anastasijević

    2012-11-01

    Full Text Available This paper evaluates the degradation of audio content for a perceptible removable watermark. Two different approaches to embedding the watermark in the spectral domain were investigated. The frequencies for watermark embedding are chosen according to a pseudorandom sequence making the methods robust. Consequentially, the lower quality audio can be used for promotional purposes. For a fee, the watermark can be removed with a secret watermarking key. Objective and subjective testing was conducted in order to measure degradation level for the watermarked music samples and to examine residual distortion for different parameters of the watermarking algorithm and different music genres.

  2. Combining multiple observations of audio signals

    Science.gov (United States)

    Bayram, Ilker

    2013-09-01

    We consider the problem of reconstructing an audio signal from multiple observations, each of which is contaminated with time-varying noise. Assuming that the time-variation is different for each observation, we propose an estimation formulation that can adapt to these changes. Specifically, we postulate a parametric reconstruction and choose the parameters so that the reconstruction minimizes a cost function. The cost function is selected so that audio signals are penalized less compared to arbitrary signals with the same energy. As cost functions, we experiment with a recently proposed prior as well as mixed norms placed on the short time Fourier coefficients.

  3. Personalized Audio Systems - a Bayesian Approach

    DEFF Research Database (Denmark)

    Nielsen, Jens Brehm; Jensen, Bjørn Sand; Hansen, Toke Jansen

    2013-01-01

    Modern audio systems are typically equipped with several user-adjustable parameters unfamiliar to most users listening to the system. To obtain the best possible setting, the user is forced into multi-parameter optimization with respect to the users's own objective and preference. To address this......, the present paper presents a general inter-active framework for personalization of such audio systems. The framework builds on Bayesian Gaussian process regression in which a model of the users's objective function is updated sequentially. The parameter setting to be evaluated in a given trial is selected...

  4. Enhancing Navigation Skills through Audio Gaming.

    Science.gov (United States)

    Sánchez, Jaime; Sáenz, Mauricio; Pascual-Leone, Alvaro; Merabet, Lotfi

    2010-01-01

    We present the design, development and initial cognitive evaluation of an Audio-based Environment Simulator (AbES). This software allows a blind user to navigate through a virtual representation of a real space for the purposes of training orientation and mobility skills. Our findings indicate that users feel satisfied and self-confident when interacting with the audio-based interface, and the embedded sounds allow them to correctly orient themselves and navigate within the virtual world. Furthermore, users are able to transfer spatial information acquired through virtual interactions into real world navigation and problem solving tasks.

  5. Enhancing Navigation Skills through Audio Gaming

    Science.gov (United States)

    Sánchez, Jaime; Sáenz, Mauricio; Pascual-Leone, Alvaro; Merabet, Lotfi

    2014-01-01

    We present the design, development and initial cognitive evaluation of an Audio-based Environment Simulator (AbES). This software allows a blind user to navigate through a virtual representation of a real space for the purposes of training orientation and mobility skills. Our findings indicate that users feel satisfied and self-confident when interacting with the audio-based interface, and the embedded sounds allow them to correctly orient themselves and navigate within the virtual world. Furthermore, users are able to transfer spatial information acquired through virtual interactions into real world navigation and problem solving tasks. PMID:25505796

  6. Non Audio-Video gesture recognition system

    DEFF Research Database (Denmark)

    Craciunescu, Razvan; Mihovska, Albena Dimitrova; Kyriazakos, Sofoklis

    2016-01-01

    recognition from the face and hand gesture recognition. Gesture recognition enables humans to communicate with the machine and interact naturally without any mechanical devices. This paper investigates the possibility to use non-audio/video sensors in order to design a low-cost gesture recognition device...... that can be connected to any computer on the market. The paper proposes an equation that relates the distance and voltage for a Sharp GP2Y0A21 and GP2D120 sensors in the situation that a hand is used as the reflective object. In the end, the presented system is compared with other audio/video system...

  7. Overview of the audio description in spanish DTT channels

    Directory of Open Access Journals (Sweden)

    Francisco José González

    2014-09-01

    Full Text Available This paper presents an analysis of current practices in audio description in Spanish TV channels. The results of this research show that in some channels the audio description is broadcasted for ‘receiver mix audio description’ while in other channels the alternative used is ‘broadcaster mix audio description’. The problems detected for the activation of audio description in users’ TVs can be solved applying some enhancement to signaling information used by broadcasters in their DVB TV channels. Finally, some recommendations for the users are included to present the key aspects to audio description activation in their TVs.

  8. Reviews on Technology and Standard of Spatial Audio Coding

    Directory of Open Access Journals (Sweden)

    Ikhwana Elfitri

    2017-03-01

    Full Text Available Market demands on a more impressive entertainment media have motivated for delivery of three dimensional (3D audio content to home consumers through Ultra High Definition TV (UHDTV, the next generation of TV broadcasting, where spatial audio coding plays fundamental role. This paper reviews fundamental concept on spatial audio coding which includes technology, standard, and application. Basic principle of object-based audio reproduction system will also be elaborated, compared to the traditional channel-based system, to provide good understanding on this popular interactive audio reproduction system which gives end users flexibility to render their own preferred audio composition.

  9. Audio wiring guide how to wire the most popular audio and video connectors

    CERN Document Server

    Hechtman, John

    2012-01-01

    Whether you're a pro or an amateur, a musician or into multimedia, you can't afford to guess about audio wiring. The Audio Wiring Guide is a comprehensive, easy-to-use guide that explains exactly what you need to know. No matter the size of your wiring project or installation, this handy tool provides you with the essential information you need and the techniques to use it. Using The Audio Wiring Guide is like having an expert at your side. By following the clear, step-by-step directions, you can do professional-level work at a fraction of the cost.

  10. Frequency Compensation of an SOI Bipolar-CMOS-DMOS Car Audio PA

    NARCIS (Netherlands)

    van der Zee, Ronan A.R.; van Heeswijk, R.

    2006-01-01

    A car audio PA uses a frequency-compensation scheme that avoids large compensation capacitors while retaining the bandwidth and stable load range of nested Miller compensation. The THD is 0.005% at 1kHz and 10W output power. The SNR is 108dB and the amplifier is stable for any passive load up to

  11. All About Audio Equalization: Solutions and Frontiers

    Directory of Open Access Journals (Sweden)

    Vesa Välimäki

    2016-05-01

    Full Text Available Audio equalization is a vast and active research area. The extent of research means that one often cannot identify the preferred technique for a particular problem. This review paper bridges those gaps, systemically providing a deep understanding of the problems and approaches in audio equalization, their relative merits and applications. Digital signal processing techniques for modifying the spectral balance in audio signals and applications of these techniques are reviewed, ranging from classic equalizers to emerging designs based on new advances in signal processing and machine learning. Emphasis is placed on putting the range of approaches within a common mathematical and conceptual framework. The application areas discussed herein are diverse, and include well-defined, solvable problems of filter design subject to constraints, as well as newly emerging challenges that touch on problems in semantics, perception and human computer interaction. Case studies are given in order to illustrate key concepts and how they are applied in practice. We also recommend preferred signal processing approaches for important audio equalization problems. Finally, we discuss current challenges and the uncharted frontiers in this field. The source code for methods discussed in this paper is made available at https://code.soundsoftware.ac.uk/projects/allaboutaudioeq.

  12. Spatial audio quality perception (part 2)

    DEFF Research Database (Denmark)

    Conetta, R.; Brookes, T.; Rumsey, F.

    2015-01-01

    location, envelopment, coverage angle, ensemble width, and spaciousness. They can also impact timbre, and changes to timbre can then influence spatial perception. Previously obtained data was used to build a regression model of perceived spatial audio quality in terms of spatial and timbral metrics...

  13. Audio/Visual Ratios in Commercial Filmstrips.

    Science.gov (United States)

    Gulliford, Nancy L.

    Developed by the Westinghouse Electric Corporation, Video Audio Compressed (VIDAC) is a compressed time, variable rate, still picture television system. This technology made it possible for a centralized library of audiovisual materials to be transmitted over a television channel in very short periods of time. In order to establish specifications…

  14. Audio Signal Quantization Companding Laws Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Aleksei A. Matskaniuk

    2012-05-01

    Full Text Available We describe the results of research on the effectiveness of the optimal in the sense of minimum error variance quantization scale audio playback (Lloyd-Max algorithm, and scales based on the A and Mu-law companding.

  15. CERN automatic audio-conference service

    Science.gov (United States)

    Sierra Moral, Rodrigo

    2010-04-01

    Scientists from all over the world need to collaborate with CERN on a daily basis. They must be able to communicate effectively on their joint projects at any time; as a result telephone conferences have become indispensable and widely used. Managed by 6 operators, CERN already has more than 20000 hours and 5700 audio-conferences per year. However, the traditional telephone based audio-conference system needed to be modernized in three ways. Firstly, to provide the participants with more autonomy in the organization of their conferences; secondly, to eliminate the constraints of manual intervention by operators; and thirdly, to integrate the audio-conferences into a collaborative working framework. The large number, and hence cost, of the conferences prohibited externalization and so the CERN telecommunications team drew up a specification to implement a new system. It was decided to use a new commercial collaborative audio-conference solution based on the SIP protocol. The system was tested as the first European pilot and several improvements (such as billing, security, redundancy...) were implemented based on CERN's recommendations. The new automatic conference system has been operational since the second half of 2006. It is very popular for the users and has doubled the number of conferences in the past two years.

  16. Utilization of Nonlinear Converters for Audio Amplification

    DEFF Research Database (Denmark)

    Iversen, Niels; Birch, Thomas; Knott, Arnold

    2012-01-01

    . The introduction of non-linear converters for audio amplication defeats this limitation. A Cuk converter, designed to deliver an AC peak output voltage twice the supply voltage, is presented in this paper. A 3V prototype has been developed to prove the concept. The prototype shows that it is possible to achieve...

  17. Providing Students with Formative Audio Feedback

    Science.gov (United States)

    Brearley, Francis Q.; Cullen, W. Rod

    2012-01-01

    The provision of timely and constructive feedback is increasingly challenging for busy academics. Ensuring effective student engagement with feedback is equally difficult. Increasingly, studies have explored provision of audio recorded feedback to enhance effectiveness and engagement with feedback. Few, if any, of these focus on purely formative…

  18. An ESL Audio-Script Writing Workshop

    Science.gov (United States)

    Miller, Carla

    2012-01-01

    The roles of dialogue, collaborative writing, and authentic communication have been explored as effective strategies in second language writing classrooms. In this article, the stages of an innovative, multi-skill writing method, which embeds students' personal voices into the writing process, are explored. A 10-step ESL Audio Script Writing Model…

  19. Agency Video, Audio and Imagery Library

    Science.gov (United States)

    Grubbs, Rodney

    2015-01-01

    The purpose of this presentation was to inform the ISS International Partners of the new NASA Agency Video, Audio and Imagery Library (AVAIL) website. AVAIL is a new resource for the public to search for and download NASA-related imagery, and is not intended to replace the current process by which the International Partners receive their Space Station imagery products.

  20. Audio Journal in an ELT Context

    Directory of Open Access Journals (Sweden)

    Neşe Aysin Siyli

    2012-09-01

    Full Text Available It is widely acknowledged that one of the most serious problems students of English as a foreign language face is their deprivation of practicing the language outside the classroom. Generally, the classroom is the sole environment where they can practice English, which by its nature does not provide rich setting to help students develop their competence by putting the language into practice. Motivated by this need, this descriptive study investigated the impact of audio dialog journals on students’ speaking skills. It also aimed to gain insights into students’ and teacher’s opinions on keeping audio dialog journals outside the class. The data of the study developed from student and teacher audio dialog journals, student written feedbacks, interviews held with the students, and teacher observations. The descriptive analysis of the data revealed that audio dialog journals served a number of functions ranging from cognitive to linguistic, from pedagogical to psychological, and social. The findings and pedagogical implications of the study are discussed in detail.

  1. Consuming audio: an introduction to Tweak Theory

    NARCIS (Netherlands)

    Perlman, Marc

    2014-01-01

    abstractAudio technology is a medium for music, and when we pay attention to it we tend to speculate about its effects on the music it transmits. By now there are well-established traditions of commentary (many of them critical) about the impact of musical reproduction on musical production.

  2. CERN automatic audio-conference service

    International Nuclear Information System (INIS)

    Sierra Moral, Rodrigo

    2010-01-01

    Scientists from all over the world need to collaborate with CERN on a daily basis. They must be able to communicate effectively on their joint projects at any time; as a result telephone conferences have become indispensable and widely used. Managed by 6 operators, CERN already has more than 20000 hours and 5700 audio-conferences per year. However, the traditional telephone based audio-conference system needed to be modernized in three ways. Firstly, to provide the participants with more autonomy in the organization of their conferences; secondly, to eliminate the constraints of manual intervention by operators; and thirdly, to integrate the audio-conferences into a collaborative working framework. The large number, and hence cost, of the conferences prohibited externalization and so the CERN telecommunications team drew up a specification to implement a new system. It was decided to use a new commercial collaborative audio-conference solution based on the SIP protocol. The system was tested as the first European pilot and several improvements (such as billing, security, redundancy...) were implemented based on CERN's recommendations. The new automatic conference system has been operational since the second half of 2006. It is very popular for the users and has doubled the number of conferences in the past two years.

  3. Restoration of Local Degradations in Audio Signals

    Directory of Open Access Journals (Sweden)

    M. Brejl

    1996-09-01

    Full Text Available The paper presents an algorithm for restoration of local degradations in audio signals. The theoretical foundations and basic suggestions of this algorithm were published in [1]. A complete description of restoration process and some improvements are presented here.

  4. Extracting meaning from audio signals - a machine learning approach

    DEFF Research Database (Denmark)

    Larsen, Jan

    2007-01-01

    * Machine learning framework for sound search * Genre classification * Music and audio separation * Wind noise suppression......* Machine learning framework for sound search * Genre classification * Music and audio separation * Wind noise suppression...

  5. Software tools for object-based audio production using the Audio Definition Model

    OpenAIRE

    Matthias , Geier; Carpentier , Thibaut; Noisternig , Markus; Warusfel , Olivier

    2017-01-01

    International audience; We present a publicly available set of tools for the integration of the Audio Definition Model (ADM) in production workflows. ADM is an open metadata model for the description of channel-, scene-, and object-based media within a Broadcast Wave Format (BWF) container. The software tools were developed within the European research project ORPHEUS (https://orpheus-audio.eu/) that aims at developing new end-to-end object-based media chains for broadcast. These tools allow ...

  6. Improved Convolutive and Under-Determined Blind Audio Source Separation with MRF Smoothing.

    Science.gov (United States)

    Zdunek, Rafał

    2013-01-01

    Convolutive and under-determined blind audio source separation from noisy recordings is a challenging problem. Several computational strategies have been proposed to address this problem. This study is concerned with several modifications to the expectation-minimization-based algorithm, which iteratively estimates the mixing and source parameters. This strategy assumes that any entry in each source spectrogram is modeled using superimposed Gaussian components, which are mutually and individually independent across frequency and time bins. In our approach, we resolve this issue by considering a locally smooth temporal and frequency structure in the power source spectrograms. Local smoothness is enforced by incorporating a Gibbs prior in the complete data likelihood function, which models the interactions between neighboring spectrogram bins using a Markov random field. Simulations using audio files derived from stereo audio source separation evaluation campaign 2008 demonstrate high efficiency with the proposed improvement.

  7. Progressive Syntax-Rich Coding of Multichannel Audio Sources

    Directory of Open Access Journals (Sweden)

    Dai Yang

    2003-09-01

    Full Text Available Being able to transmit the audio bitstream progressively is a highly desirable property for network transmission. MPEG-4 version 2 audio supports fine grain bit rate scalability in the generic audio coder (GAC. It has a bit-sliced arithmetic coding (BSAC tool, which provides scalability in the step of 1 Kbps per audio channel. There are also several other scalable audio coding methods, which have been proposed in recent years. However, these scalable audio tools are only available for mono and stereo audio material. Little work has been done on progressive coding of multichannel audio sources. MPEG advanced audio coding (AAC is one of the most distinguished multichannel digital audio compression systems. Based on AAC, we develop in this work a progressive syntax-rich multichannel audio codec (PSMAC. It not only supports fine grain bit rate scalability for the multichannel audio bitstream but also provides several other desirable functionalities. A formal subjective listening test shows that the proposed algorithm achieves an excellent performance at several different bit rates when compared with MPEG AAC.

  8. Progressive Syntax-Rich Coding of Multichannel Audio Sources

    Science.gov (United States)

    Yang, Dai; Ai, Hongmei; Kyriakakis, Chris; Kuo, C.-C. Jay

    2003-12-01

    Being able to transmit the audio bitstream progressively is a highly desirable property for network transmission. MPEG- [InlineEquation not available: see fulltext.] version [InlineEquation not available: see fulltext.] audio supports fine grain bit rate scalability in the generic audio coder (GAC). It has a bit-sliced arithmetic coding (BSAC) tool, which provides scalability in the step of 1 Kbps per audio channel. There are also several other scalable audio coding methods, which have been proposed in recent years. However, these scalable audio tools are only available for mono and stereo audio material. Little work has been done on progressive coding of multichannel audio sources. MPEG advanced audio coding (AAC) is one of the most distinguished multichannel digital audio compression systems. Based on AAC, we develop in this work a progressive syntax-rich multichannel audio codec (PSMAC). It not only supports fine grain bit rate scalability for the multichannel audio bitstream but also provides several other desirable functionalities. A formal subjective listening test shows that the proposed algorithm achieves an excellent performance at several different bit rates when compared with MPEG AAC.

  9. Audio Mining with emphasis on Music Genre Classification

    DEFF Research Database (Denmark)

    Meng, Anders

    2004-01-01

    etc. is receiving quite a lot of attention. The first breakthough in audio mining was created by MuscleFish in 1996, a simple audio retrieval system. With the increasing amount of audio material being accessible through the web, e.g. Apple's iTunes (700,000+ songs), Sony, Amazon, new methods...

  10. 47 CFR 10.520 - Common audio attention signal.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Common audio attention signal. 10.520 Section... Equipment Requirements § 10.520 Common audio attention signal. A Participating CMS Provider and equipment manufacturers may only market devices for public use under part 10 that include an audio attention signal that...

  11. Audio Books in the Nigerian Higher Educational System: To be ...

    African Journals Online (AJOL)

    This study discusses audio books from the point of view of an innovation. It discusses the advantages and disadvantages of audio books. It examined students' familiarization with audio books and their perception about its being introduced into the school system. It was found out that Nigerian students are already familiar ...

  12. Modelling and analysis of a high-performance Class D audio amplifier using unipolar pulse-width-modulation

    Science.gov (United States)

    Zhou, Zekun; Shi, Yue; Ming, Xin; Zhang, Bo; Li, Zhaoji; Chen, Zao

    2012-02-01

    A high-performance class D audio amplifier using unipolar pulse-width-modulation (PWM) with double-sided natural sampling is presented in this article. In order to comprehend and design the system properly, the class D audio amplifier is modelled and analysed. A wide range triangle-wave signal with good linearity and magnitude proportional to supply voltage is embedded in the proposed class D audio amplifier for maximum output power, high power supply rejection ratio (PSRR) and low total harmonic distortion (THD). Design results based on CSMC 0.5-µm 5-V complementary metal-oxide-semiconductor process demonstrate that the proposed class D audio amplifier can operate with supply voltage in the range 2.4-5.5 V and supports 2.8 W output power from a 5.5 V supply; the maximum efficiency is above 95%, the PSRR is -82 dB, the signal-to-noise ratio (SNR) is 97 dB and the total harmonic distortion plus noise (THD+N) is less than 0.1% between 20 and 20 kHz with output power 0.4 W; the quiescent current without load is 1.8 mA, and the shutdown current is 0.01 µA. The active area of the class-D audio power amplifier is 1.5 mm × 1.5 mm.

  13. Energy Use of Home Audio Products in the U.S.

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, K.B.; Meier, A.K.

    1999-12-01

    We conducted a bottom-up analysis using stock and usage estimates from secondary sources, and our own power measurements. We measured power levels of the most common audio products in their most commonly used operating modes. We found that the combined energy consumption of standby, idle, and play modes of clock radios, portable stereos, compact stereos, and component stereos was 20 TWh/yr, representing about 1.8% of the 1998 national residential electricity consumption.

  14. acceleration observed in an audio air gas discharge

    International Nuclear Information System (INIS)

    Ragheb, M.S.

    2010-01-01

    an audio air gas discharge enclosed in a pyrex glass of 34 mm diameter and 25 cm long , lead to trace the occurrence of an unusual phenomenon. injected relative huge light spots of intense brightness, distributed regularly on the contour and in the center of one of the discharge electrodes, are observed. very high heat is pronounced on both electrodes, while, one of them is higher than the other it attains 660 degree C in 3-4 minutes. series of photographs and registered video films define and clarify the sequence of events that describe the observed phenomenon. the plasma is created by applying an audio power through the electrodes of an air gas discharge of 10 khz and up to 500 watts power supply. the discharge voltage is up to 900 volts: the discharge current flowing through the plasma attains 360 mA. it is found that the discharge system must attain its optimal working conditions in order to produce the amazing phenomena. the obtained plasma is classified as the maximum conditions borders of a γ-discharge type. at these conditions, the corresponding maximum electron temperature and density are 16 eV and 10 15 cm -3 respectively . the observation system succeeded to reveal and to clarify the sequence of the phenomenon events. in addition, by means of the scanning electron microscope and the energy dispersive x- ray systems, the effects on the electrodes surface are investigated and analyzed. the optical observations, in conjunction with the micrograph and surface microanalysis,demonstrate the collision occurrence, of powered agglomerations groups, to the electrode surface. detailed interpretation of that phenomenon suggests a molecular acceleration gaining their energy from the formed plasma due to optimal discharge working conditions. as a consequence, due to the ions agglomerates size this procedure could be considered as a mesoscopic acceleration technique.

  15. Audio coding in wireless acoustic sensor networks

    DEFF Research Database (Denmark)

    Zahedi, Adel; Østergaard, Jan; Jensen, Søren Holdt

    2015-01-01

    ) for the resulting remote DSC problem under covariance matrix distortion constraints. We further show that for this problem, the Gaussian source is the worst to code. Thus, the Gaussian RDF provides an upper bound to other sources such as audio signals. We then turn our attention to audio signals. We consider......In this paper, we consider the problem of source coding for a wireless acoustic sensor network where each node in the network makes its own noisy measurement of the sound field, and communicates with other nodes in the network by sending and receiving encoded versions of the measurements. To make...... use of the correlation between the sources available at the nodes, we consider the possibility of combining the measurement and the received messages into one single message at each node instead of forwarding the received messages and separate encoding of the measurement. Moreover, to exploit...

  16. Enlace optoelectrónico de audio

    OpenAIRE

    García Lozano, Jesús

    2012-01-01

    En este proyecto se diseña e implementa un sistema capaz de transmitir audio mediante luz infrarroja. Se pueden diferenciar dos grandes partes del proyecto, una el módulo emisor y la otra el módulo receptor. La señal es introducida en el módulo emisor a partir de cualquier reproductor de audio. Esta señal es sometida a un proceso de modulación FM para mejorar la comunicación entre emisor y receptor, puesto que la transmisión de la señal en banda base es más vulnerable a ruidos. Una vez modula...

  17. Basic Concepts in Augmented Reality Audio

    OpenAIRE

    Lemordant, Jacques

    2010-01-01

    International audience; The basic difference between real and virtual sound environments is that virtual sounds are originating from another environment or are artificially created, whereas the real sounds are the natural existing sounds in the user's own environment. Augmented Reality Audio combines these aspects in a way where real and virtual sound scenes are mixed so that virtual sounds are perceived as an extension or a complement to the natural ones.

  18. Personalized Audio Systems - a Bayesian Approach

    DEFF Research Database (Denmark)

    Nielsen, Jens Brehm; Jensen, Bjørn Sand; Hansen, Toke Jansen

    2013-01-01

    , the present paper presents a general inter-active framework for personalization of such audio systems. The framework builds on Bayesian Gaussian process regression in which a model of the users's objective function is updated sequentially. The parameter setting to be evaluated in a given trial is selected...... are optimized using the proposed framework. Twelve test subjects obtain a personalized setting with the framework, and these settings are signicantly preferred to those obtained with random experimentation....

  19. New musical organology : the audio-games

    OpenAIRE

    Zénouda , Hervé

    2012-01-01

    International audience; This article aims to shed light on a new and emerging creative field: " Audio Games, " a crossroad between video games and computer music. Today, a plethora of tiny applications, which propose entertaining audiovisual experiences with a preponderant sound dimension, are available for game consoles, computers, and mobile phones. These experiences represent a new universe where the gameplay of video games is applied to musical composition, hence creating new links betwee...

  20. Emerging topics in translation: Audio description

    OpenAIRE

    Perego, Elisa

    2012-01-01

    The volume deals with several aspects of audio description for the blind and sight impaired which came to the surface during the AD session of the conference Emerging topics in translation and interpreting held at the Department of Language, Translation and Interpreting Studies of the University of Trieste, 16-18 June 2010. The topics dealt with in the volume range from the more established (linguistic analysis of ADs in various languages, strategies to overcome possible obs...

  1. Digitisation of the CERN Audio Archives

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    Since the creation of CERN in 1954 until mid 1980s, the audiovisual service has recorded hundreds of hours of moments of life at CERN on audio tapes. These moments range from inaugurations of new facilities to VIP speeches and general interest cultural seminars The preservation process started in June 2005 On these pictures, we see Waltraud Hug working on an open-reel tape.

  2. Design of progressive syntax-rich multichannel audio codec

    Science.gov (United States)

    Yang, Dai; Ai, Hongmei; Kyriakakis, Christos; Kuo, C.-C. Jay

    2001-12-01

    Being able to transmit the audio bitstream progressively is a highly desirable property for network transmission. MPEG-4 version-2 audio supports fine grain bit rate scalability in the Generic Audio Coder (GAC). It has a Bit-Sliced Arithmetic Coding (BSAC) tool, which provides scalability in the step of 1kbit/sec per audio channel. However, this fine grain scalability tool is only available for mono and stereo audio material. Not much work has been done on progressively transmitting multichannel audio sources. MPEG Advanced Audio Coding (AAC) is one of the most distinguished multichannel digital audio compression systems. Based on AAC, we develop a progressive syntax-rich multichannel audio codec in this work. It not only supports fine grain bit rate scalability for the multichannel audio bitstream, but also provides several other desirable functionalities. A formal subjective listening test shows that the proposed algorithm achieves a better performance at several different bit rates when compared with MPEG-4 BSAC for the mono audio sources.

  3. Detection Of Alterations In Audio Files Using Spectrograph Analysis

    Directory of Open Access Journals (Sweden)

    Anandha Krishnan G

    2015-08-01

    Full Text Available The corresponding study was carried out to detect changes in audio file using spectrograph. An audio file format is a file format for storing digital audio data on a computer system. A sound spectrograph is a laboratory instrument that displays a graphical representation of the strengths of the various component frequencies of a sound as time passes. The objectives of the study were to find the changes in spectrograph of audio after altering them to compare altering changes with spectrograph of original files and to check for similarity and difference in mp3 and wav. Five different alterations were carried out on each audio file to analyze the differences between the original and the altered file. For altering the audio file MP3 or WAV by cutcopy the file was opened in Audacity. A different audio was then pasted to the audio file. This new file was analyzed to view the differences. By adjusting the necessary parameters the noise was reduced. The differences between the new file and the original file were analyzed. By adjusting the parameters from the dialog box the necessary changes were made. The edited audio file was opened in the software named spek where after analyzing a graph is obtained of that particular file which is saved for further analysis. The original audio graph received was combined with the edited audio file graph to see the alterations.

  4. Comparing audio and video data for rating communication.

    Science.gov (United States)

    Williams, Kristine; Herman, Ruth; Bontempo, Daniel

    2013-09-01

    Video recording has become increasingly popular in nursing research, adding rich nonverbal, contextual, and behavioral information. However, benefits of video over audio data have not been well established. We compared communication ratings of audio versus video data using the Emotional Tone Rating Scale. Twenty raters watched video clips of nursing care and rated staff communication on 12 descriptors that reflect dimensions of person-centered and controlling communication. Another group rated audio-only versions of the same clips. Interrater consistency was high within each group with Interclass Correlation Coefficient (ICC) (2,1) for audio .91, and video = .94. Interrater consistency for both groups combined was also high with ICC (2,1) for audio and video = .95. Communication ratings using audio and video data were highly correlated. The value of video being superior to audio-recorded data should be evaluated in designing studies evaluating nursing care.

  5. AudioMUD: a multiuser virtual environment for blind people.

    Science.gov (United States)

    Sánchez, Jaime; Hassler, Tiago

    2007-03-01

    A number of virtual environments have been developed during the last years. Among them there are some applications for blind people based on different type of audio, from simple sounds to 3-D audio. In this study, we pursued a different approach. We designed AudioMUD by using spoken text to describe the environment, navigation, and interaction. We have also introduced some collaborative features into the interaction between blind users. The core of a multiuser MUD game is a networked textual virtual environment. We developed AudioMUD by adding some collaborative features to the basic idea of a MUD and placed a simulated virtual environment inside the human body. This paper presents the design and usability evaluation of AudioMUD. Blind learners were motivated when interacted with AudioMUD and helped to improve the interaction through audio and interface design elements.

  6. Securing Digital Audio using Complex Quadratic Map

    Science.gov (United States)

    Suryadi, MT; Satria Gunawan, Tjandra; Satria, Yudi

    2018-03-01

    In This digital era, exchanging data are common and easy to do, therefore it is vulnerable to be attacked and manipulated from unauthorized parties. One data type that is vulnerable to attack is digital audio. So, we need data securing method that is not vulnerable and fast. One of the methods that match all of those criteria is securing the data using chaos function. Chaos function that is used in this research is complex quadratic map (CQM). There are some parameter value that causing the key stream that is generated by CQM function to pass all 15 NIST test, this means that the key stream that is generated using this CQM is proven to be random. In addition, samples of encrypted digital sound when tested using goodness of fit test are proven to be uniform, so securing digital audio using this method is not vulnerable to frequency analysis attack. The key space is very huge about 8.1×l031 possible keys and the key sensitivity is very small about 10-10, therefore this method is also not vulnerable against brute-force attack. And finally, the processing speed for both encryption and decryption process on average about 450 times faster that its digital audio duration.

  7. Audio Spatial Representation Around the Body.

    Science.gov (United States)

    Aggius-Vella, Elena; Campus, Claudio; Finocchietti, Sara; Gori, Monica

    2017-01-01

    Studies have found that portions of space around our body are differently coded by our brain. Numerous works have investigated visual and auditory spatial representation, focusing mostly on the spatial representation of stimuli presented at head level, especially in the frontal space. Only few studies have investigated spatial representation around the entire body and its relationship with motor activity. Moreover, it is still not clear whether the space surrounding us is represented as a unitary dimension or whether it is split up into different portions, differently shaped by our senses and motor activity. To clarify these points, we investigated audio localization of dynamic and static sounds at different body levels. In order to understand the role of a motor action in auditory space representation, we asked subjects to localize sounds by pointing with the hand or the foot, or by giving a verbal answer. We found that the audio sound localization was different depending on the body part considered. Moreover, a different pattern of response was observed when subjects were asked to make actions with respect to the verbal responses. These results suggest that the audio space around our body is split in various spatial portions, which are perceived differently: front, back, around chest, and around foot, suggesting that these four areas could be differently modulated by our senses and our actions.

  8. Audio-visual speech experience with age influences perceived audio-visual asynchrony in speech.

    Science.gov (United States)

    Alm, Magnus; Behne, Dawn

    2013-10-01

    Previous research indicates that perception of audio-visual (AV) synchrony changes in adulthood. Possible explanations for these age differences include a decline in hearing acuity, a decline in cognitive processing speed, and increased experience with AV binding. The current study aims to isolate the effect of AV experience by comparing synchrony judgments from 20 young adults (20 to 30 yrs) and 20 normal-hearing middle-aged adults (50 to 60 yrs), an age range for which a decline of cognitive processing speed is expected to be minimal. When presented with AV stop consonant syllables with asynchronies ranging from 440 ms audio-lead to 440 ms visual-lead, middle-aged adults showed significantly less tolerance for audio-lead than young adults. Middle-aged adults also showed a greater shift in their point of subjective simultaneity than young adults. Natural audio-lead asynchronies are arguably more predictable than natural visual-lead asynchronies, and this predictability may render audio-lead thresholds more prone to experience-related fine-tuning.

  9. Programmable Power Supply for AC Switching Magnet of Proton Accelerator

    CERN Document Server

    Jeong, Seong-Hun; Kang Heung Sik; Lee, Chi-Hwan; Lee, Hong-Gi; Park, Ki-Hyeon; Ryu, Chun-Kil; Sik Han, Hong; Suck Suh, Hyung

    2005-01-01

    The 100-MeV PEFP proton linac has two proton beam extraction lines for user' experiment. Each extraction line has 5 beamlines and has 5 Hz operating frequency. An AC switching magnet is used to distribute the proton beam to the 5 beamlines, An AC switching magnet is powered by PWM-controlled bipolar switching-mode converters. This converter is designed to operate at ±350A, 5 Hz programmable step output. The power supply is employed IGBT module and has controlled by a DSP (Digital Signal Process). This paper describes the design and test results of the power supply.

  10. Content-based classification and retrieval of audio

    Science.gov (United States)

    Zhang, Tong; Kuo, C.-C. Jay

    1998-10-01

    An on-line audio classification and segmentation system is presented in this research, where audio recordings are classified and segmented into speech, music, several types of environmental sounds and silence based on audio content analysis. This is the first step of our continuing work towards a general content-based audio classification and retrieval system. The extracted audio features include temporal curves of the energy function,the average zero- crossing rate, the fundamental frequency of audio signals, as well as statistical and morphological features of these curves. The classification result is achieved through a threshold-based heuristic procedure. The audio database that we have built, details of feature extraction, classification and segmentation procedures, and experimental results are described. It is shown that, with the proposed new system, audio recordings can be automatically segmented and classified into basic types in real time with an accuracy of over 90 percent. Outlines of further classification of audio into finer types and a query-by-example audio retrieval system on top of the coarse classification are also introduced.

  11. Le registrazioni audio dell’archivio Luigi Nono di Venezia

    Directory of Open Access Journals (Sweden)

    Luca Cossettini

    2009-11-01

    Full Text Available The audio recordings of the Luigi Nono Archive in Venice: guidelines for preservation and critical edition of audio documentsStudying audio recordings brings us back to ancient source verification problems that too often one thinks are overcome by the technical reproduction of sound. Au-dio signal is “fixed” on a specific carrier (tape, disc etc with a specific audio format (speed, number of tracks etc; the choice of support and format during the first “memorizing” process and the following copying processes is a subjective and, in case of copying, an interpretative operation conducted within a continuously evolv-ing audio technology. What we listen to today is the result of a transmission process that unavoidably transforms the original acoustic event and the documents that memorize it. Audio recording is no way a timeless and immutable fixing process. It is therefore necessary to study the transmission processes and to reconstruct the au-dio document tradition. The re-recording of the tapes of the Archivio Luigi Nono, conducted by the Audio Labs of the DAMS Musica of the University of Udine, of-fers clear examples of the technical and musicological interpretative problems one can find when he works with audio recordings.

  12. Exploring the Implementation of Steganography Protocols on Quantum Audio Signals

    Science.gov (United States)

    Chen, Kehan; Yan, Fei; Iliyasu, Abdullah M.; Zhao, Jianping

    2018-02-01

    Two quantum audio steganography (QAS) protocols are proposed, each of which manipulates or modifies the least significant qubit (LSQb) of the host quantum audio signal that is encoded as an FRQA (flexible representation of quantum audio) audio content. The first protocol (i.e. the conventional LSQb QAS protocol or simply the cLSQ stego protocol) is built on the exchanges between qubits encoding the quantum audio message and the LSQb of the amplitude information in the host quantum audio samples. In the second protocol, the embedding procedure to realize it implants information from a quantum audio message deep into the constraint-imposed most significant qubit (MSQb) of the host quantum audio samples, we refer to it as the pseudo MSQb QAS protocol or simply the pMSQ stego protocol. The cLSQ stego protocol is designed to guarantee high imperceptibility between the host quantum audio and its stego version, whereas the pMSQ stego protocol ensures that the resulting stego quantum audio signal is better immune to illicit tampering and copyright violations (a.k.a. robustness). Built on the circuit model of quantum computation, the circuit networks to execute the embedding and extraction algorithms of both QAS protocols are determined and simulation-based experiments are conducted to demonstrate their implementation. Outcomes attest that both protocols offer promising trade-offs in terms of imperceptibility and robustness.

  13. Elicitation of attributes for the evaluation of audio-on audio-interference

    DEFF Research Database (Denmark)

    Francombe, Jon; Mason, R.; Dewhirst, M.

    2014-01-01

    An experiment to determine the perceptual attributes of the experience of listening to a target audio program in the presence of an audio interferer was performed. The first stage was a free elicitation task in which a total of 572 phrases were produced. In the second stage, a consensus vocabulary...... procedure was used to reduce these phrases into a comprehensive set of attributes. Groups of experienced and inexperienced listeners determined nine and eight attributes, respectively. These attribute sets were combined by the listeners to produce a final set of 12 attributes: masking, calming, distraction...

  14. Real-Time Perceptual Model for Distraction in Interfering Audio-on-Audio Scenarios

    DEFF Research Database (Denmark)

    Rämö, Jussi; Bech, Søren; Jensen, Søren Holdt

    2017-01-01

    model. Thus, while providing similar accuracy as the previous model, the proposed model can be run in real time. The proposed distraction model can be used as a tool for evaluating and optimizing sound-zone systems. Furthermore, the real-time capability of the model introduces new possibilities......This letter proposes a real-time perceptual model predicting the experienced distraction occurring in interfering audio-on-audio situations. The proposed model improves the computational efficiency of a previous distraction model, which cannot provide predictions in real time. The chosen approach...

  15. Calibration of an audio frequency noise generator

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1966-01-01

    a noise bandwidth Bn = π/2 × (3dB bandwidth). To apply this method to low audio frequencies, the noise bandwidth of the low Q parallel resonant circuit has been found, including the effects of both series and parallel damping. The method has been used to calibrate a General Radio 1390-B noise generator...... it is used for measurement purposes. The spectral density of a noise source may be found by measuring its rms output over a known noise bandwidth. Such a bandwidth may be provided by a passive filter using accurately known elements. For example, the parallel resonant circuit with purely parallel damping has...

  16. Mixing audio concepts, practices and tools

    CERN Document Server

    Izhaki, Roey

    2013-01-01

    Your mix can make or break a record, and mixing is an essential catalyst for a record deal. Professional engineers with exceptional mixing skills can earn vast amounts of money and find that they are in demand by the biggest acts. To develop such skills, you need to master both the art and science of mixing. The new edition of this bestselling book offers all you need to know and put into practice in order to improve your mixes. Covering the entire process --from fundamental concepts to advanced techniques -- and offering a multitude of audio samples, tips and tricks, this boo

  17. Spatial audio quality perception (part 1)

    DEFF Research Database (Denmark)

    Conetta, R.; Brookes, T.; Rumsey, F.

    2015-01-01

    resulting from 48 such SAPs. Perceived degradation also depends on the particular listeners, the program content, and the listening location. For example, combining off-center listener with another SAP can reduce spatial quality significantly when compared to listening to that SAP from a central location....... The choice of the SAP can have a large influence on the degree of degradation. Taken together these findings and the quality-annotated database can guide the development of a regression model of perceived overall spatial audio quality, incorporating previously developed spatially-relevant feature...

  18. Effects for augmented reality audio headsets

    OpenAIRE

    Martí i Rabadán, Miquel

    2014-01-01

    [ANGLÈS] Augmented reality is a real-time combination of real and virtual worlds. In augmented reality audio (ARA) real surrounding sounds are mixed with virtual sound sources. In this bachelor’s degree thesis a digital, real-time hear-through system (HTS) is implemented for the acoustical transparency of an ARA headset. It is achieved by adding back the sounds that have been attenuated by the isolation characteristics of the headphone itself. The surrounding sounds are recorded on both ears...

  19. Elicitation of attributes for the evaluation of audio-on-audio interference.

    Science.gov (United States)

    Francombe, Jon; Mason, Russell; Dewhirst, Martin; Bech, Søren

    2014-11-01

    An experiment to determine the perceptual attributes of the experience of listening to a target audio program in the presence of an audio interferer was performed. The first stage was a free elicitation task in which a total of 572 phrases were produced. In the second stage, a consensus vocabulary procedure was used to reduce these phrases into a comprehensive set of attributes. Groups of experienced and inexperienced listeners determined nine and eight attributes, respectively. These attribute sets were combined by the listeners to produce a final set of 12 attributes: masking, calming, distraction, separation, confusion, annoyance, environment, chaotic, balance and blend, imagery, response to stimuli over time, and short-term response to stimuli. In the third stage, a simplified ranking procedure was used to select only the most useful and relevant attributes. Four attributes were selected: distraction, annoyance, balance and blend, and confusion. Ratings using these attributes were collected in the fourth stage, and a principal component analysis performed. This suggested two dimensions underlying the perception of an audio-on-audio interference situation: The first dimension was labeled "distraction" and accounted for 89% of the variance; the second dimension, accounting for 10% of the variance, was labeled "balance and blend."

  20. Audio-Visual, Visuo-Tactile and Audio-Tactile Correspondences in Preschoolers.

    Science.gov (United States)

    Nava, Elena; Grassi, Massimo; Turati, Chiara

    2016-01-01

    Interest in crossmodal correspondences has recently seen a renaissance thanks to numerous studies in human adults. Yet, still very little is known about crossmodal correspondences in children, particularly in sensory pairings other than audition and vision. In the current study, we investigated whether 4-5-year-old children match auditory pitch to the spatial motion of visual objects (audio-visual condition). In addition, we investigated whether this correspondence extends to touch, i.e., whether children also match auditory pitch to the spatial motion of touch (audio-tactile condition) and the spatial motion of visual objects to touch (visuo-tactile condition). In two experiments, two different groups of children were asked to indicate which of two stimuli fitted best with a centrally located third stimulus (Experiment 1), or to report whether two presented stimuli fitted together well (Experiment 2). We found sensitivity to the congruency of all of the sensory pairings only in Experiment 2, suggesting that only under specific circumstances can these correspondences be observed. Our results suggest that pitch-height correspondences for audio-visual and audio-tactile combinations may still be weak in preschool children, and speculate that this could be due to immature linguistic and auditory cues that are still developing at age five.

  1. Penguat Audio Kelas D dengan Umpan Balik Tipe Butterworth

    Directory of Open Access Journals (Sweden)

    Gunawan Dewantoro

    2016-03-01

    Full Text Available A class D amplifier would, in ideal sense, amplify signals without any noises and distortions which yield 100% efficiency and 0% Total Harmonic Distortion (THD. However, class D amplifiers have some drawbacks that lead to nonlinearity and increasing THD. Therefore, a feedback mechanism was employed to enhance THD performance of amplifier. Some feedback techniques have been using first order filter in the feedback path to retrieve audio signals. This research proposed a second order filter with Butterworth approach. A power amplifier was realized using full-bridge amplifier with MOSFETs to provide greater power. This class D amplifier was designed to meet following specifications: maximum output power up to 32.6 W with an 8 Ω load, sensitivity of 90 mV/W, frequency response ranging from 20 Hz – 20 kHz with tolerance ± 1 dB, THD as low as 1.1 %, SNR up to 90.16 dB, and efficiency of 82.1 %.

  2. [Analysis of the factors influencing the response of the skin to audio signals].

    Science.gov (United States)

    Cao, Lijia; Li, Jianwen

    2011-06-01

    Skin-hearing aid is a new type of electronic product, which can improve hearing for deaf patients. It is different from audiphones and cochlear implant. The instrument makes use of the effect of the skin response to audio signals. The working process of the instrument is as following. Firstly, the sound signal is converted to audio signal by microphone, then through the power amplifier and booster. Then the signal is transmitted to the brain via skin by electrodes. And finally the hearing is formed. As skin-hearing aid transmits signals through the skin by the electrodes, the intensity of the skin resistance becomes the main factor influencing the response of the skin to audio signal. Skin resistance depends mainly upon the stratum corneum. This article aims to discuss the factors affecting the skin resistance, such as the thickness of the stratum corneum, hydration level of stratum corneum, the relation of audio frequency and skin resistance, and the skin resistance of acupuncture points.

  3. Investigating the impact of audio instruction and audio-visual biofeedback for lung cancer radiation therapy

    Science.gov (United States)

    George, Rohini

    Lung cancer accounts for 13% of all cancers in the Unites States and is the leading cause of deaths among both men and women. The five-year survival for lung cancer patients is approximately 15%.(ACS facts & figures) Respiratory motion decreases accuracy of thoracic radiotherapy during imaging and delivery. To account for respiration, generally margins are added during radiation treatment planning, which may cause a substantial dose delivery to normal tissues and increase the normal tissue toxicity. To alleviate the above-mentioned effects of respiratory motion, several motion management techniques are available which can reduce the doses to normal tissues, thereby reducing treatment toxicity and allowing dose escalation to the tumor. This may increase the survival probability of patients who have lung cancer and are receiving radiation therapy. However the accuracy of these motion management techniques are inhibited by respiration irregularity. The rationale of this thesis was to study the improvement in regularity of respiratory motion by breathing coaching for lung cancer patients using audio instructions and audio-visual biofeedback. A total of 331 patient respiratory motion traces, each four minutes in length, were collected from 24 lung cancer patients enrolled in an IRB-approved breathing-training protocol. It was determined that audio-visual biofeedback significantly improved the regularity of respiratory motion compared to free breathing and audio instruction, thus improving the accuracy of respiratory gated radiotherapy. It was also observed that duty cycles below 30% showed insignificant reduction in residual motion while above 50% there was a sharp increase in residual motion. The reproducibility of exhale based gating was higher than that of inhale base gating. Modeling the respiratory cycles it was found that cosine and cosine 4 models had the best correlation with individual respiratory cycles. The overall respiratory motion probability distribution

  4. Newnes audio and Hi-Fi engineer's pocket book

    CERN Document Server

    Capel, Vivian

    2013-01-01

    Newnes Audio and Hi-Fi Engineer's Pocket Book, Second Edition provides concise discussion of several audio topics. The book is comprised of 10 chapters that cover different audio equipment. The coverage of the text includes microphones, gramophones, compact discs, and tape recorders. The book also covers high-quality radio, amplifiers, and loudspeakers. The book then reviews the concepts of sound and acoustics, and presents some facts and formulas relevant to audio. The text will be useful to sound engineers and other professionals whose work involves sound systems.

  5. Audio scene segmentation for video with generic content

    Science.gov (United States)

    Niu, Feng; Goela, Naveen; Divakaran, Ajay; Abdel-Mottaleb, Mohamed

    2008-01-01

    In this paper, we present a content-adaptive audio texture based method to segment video into audio scenes. The audio scene is modeled as a semantically consistent chunk of audio data. Our algorithm is based on "semantic audio texture analysis." At first, we train GMM models for basic audio classes such as speech, music, etc. Then we define the semantic audio texture based on those classes. We study and present two types of scene changes, those corresponding to an overall audio texture change and those corresponding to a special "transition marker" used by the content creator, such as a short stretch of music in a sitcom or silence in dramatic content. Unlike prior work using genre specific heuristics, such as some methods presented for detecting commercials, we adaptively find out if such special transition markers are being used and if so, which of the base classes are being used as markers without any prior knowledge about the content. Our experimental results show that our proposed audio scene segmentation works well across a wide variety of broadcast content genres.

  6. Feature Representations for Neuromorphic Audio Spike Streams.

    Science.gov (United States)

    Anumula, Jithendar; Neil, Daniel; Delbruck, Tobi; Liu, Shih-Chii

    2018-01-01

    Event-driven neuromorphic spiking sensors such as the silicon retina and the silicon cochlea encode the external sensory stimuli as asynchronous streams of spikes across different channels or pixels. Combining state-of-art deep neural networks with the asynchronous outputs of these sensors has produced encouraging results on some datasets but remains challenging. While the lack of effective spiking networks to process the spike streams is one reason, the other reason is that the pre-processing methods required to convert the spike streams to frame-based features needed for the deep networks still require further investigation. This work investigates the effectiveness of synchronous and asynchronous frame-based features generated using spike count and constant event binning in combination with the use of a recurrent neural network for solving a classification task using N-TIDIGITS18 dataset. This spike-based dataset consists of recordings from the Dynamic Audio Sensor, a spiking silicon cochlea sensor, in response to the TIDIGITS audio dataset. We also propose a new pre-processing method which applies an exponential kernel on the output cochlea spikes so that the interspike timing information is better preserved. The results from the N-TIDIGITS18 dataset show that the exponential features perform better than the spike count features, with over 91% accuracy on the digit classification task. This accuracy corresponds to an improvement of at least 2.5% over the use of spike count features, establishing a new state of the art for this dataset.

  7. Simple Solutions for Space Station Audio Problems

    Science.gov (United States)

    Wood, Eric

    2016-01-01

    Throughout this summer, a number of different projects were supported relating to various NASA programs, including the International Space Station (ISS) and Orion. The primary project that was worked on was designing and testing an acoustic diverter which could be used on the ISS to increase sound pressure levels in Node 1, a module that does not have any Audio Terminal Units (ATUs) inside it. This acoustic diverter is not intended to be a permanent solution to providing audio to Node 1; it is simply intended to improve conditions while more permanent solutions are under development. One of the most exciting aspects of this project is that the acoustic diverter is designed to be 3D printed on the ISS, using the 3D printer that was set up earlier this year. Because of this, no new hardware needs to be sent up to the station, and no extensive hardware testing needs to be performed on the ground before sending it to the station. Instead, the 3D part file can simply be uploaded to the station's 3D printer, where the diverter will be made.

  8. A continuous-time/discrete-time mixed audio-band sigma delta ADC

    Science.gov (United States)

    Yan, Liu; Siliang, Hua; Donghui, Wang; Chaohuan, Hou

    2011-01-01

    This paper introduces a mixed continuous-time/discrete-time, single-loop, fourth-order, 4-bit audio-band sigma delta ADC that combines the benefits of continuous-time and discrete-time circuits, while mitigating the challenges associated with continuous-time design. Measurement results show that the peak SNR of this ADC reaches 100 dB and the total power consumption is less than 30 mW.

  9. A continuous-time/discrete-time mixed audio-band sigma delta ADC

    International Nuclear Information System (INIS)

    Liu Yan; Hua Siliang; Wang Donghui; Hou Chaohuan

    2011-01-01

    This paper introduces a mixed continuous-time/discrete-time, single-loop, fourth-order, 4-bit audio-band sigma delta ADC that combines the benefits of continuous-time and discrete-time circuits, while mitigating the challenges associated with continuous-time design. Measurement results show that the peak SNR of this ADC reaches 100 dB and the total power consumption is less than 30 mW. (semiconductor integrated circuits)

  10. Self oscillating PWM modulators, a topological comparison

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    's work with switch mode audio power amplifiers, where linear tracking of the reference signal is of major importance. Use of the modulator topologies presented are not limited to this kind of equipment, but can be used in a very wide range of applications from very low to very high power levels....

  11. Multimedia Effects on Processing and Perception of Online News: A Study of Picture, Audio, and Video Downloads.

    Science.gov (United States)

    Sundar, S. Shyam

    2000-01-01

    Considers how multimedia enhancements affect how much individuals learn from online news websites. Suggests that picture and audio are particularly powerful psychological cues. Finds that multimedia tends to hinder memory for story content and leads to negative evaluations of the site and its content, but improves memory for advertisements.…

  12. Content Discovery from Composite Audio : An unsupervised approach

    NARCIS (Netherlands)

    Lu, L.

    2009-01-01

    In this thesis, we developed and assessed a novel robust and unsupervised framework for semantic inference from composite audio signals. We focused on the problem of detecting audio scenes and grouping them into meaningful clusters. Our approach addressed all major steps in a general process of

  13. Multilevel inverter based class D audio amplifier for capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    The reduced semiconductor voltage stress makes the multilevel inverters especially interesting, when driving capacitive transducers for audio applications. A ± 300 V flying capacitor class D audio amplifier driving a 100 nF load in the midrange region of 0.1-3.5 kHz with Total Harmonic Distortion...

  14. Tune in the Net with RealAudio.

    Science.gov (United States)

    Buchanan, Larry

    1997-01-01

    Describes how to connect to the RealAudio Web site to download a player that provides sound from Web pages to the computer through streaming technology. Explains hardware and software requirements and provides addresses for other RealAudio Web sites are provided, including weather information and current news. (LRW)

  15. Teaching Audio Playwriting: The Pedagogy of Drama Podcasting

    Science.gov (United States)

    Eshelman, David J.

    2016-01-01

    This article suggests how teaching artists can develop practical coursework in audio playwriting. To prepare students to work in the reemergent audio drama medium, the author created a seminar course called Radio Theatre Writing, taught at Arkansas Tech University in the fall of 2014. The course had three sections. First, it focused on…

  16. Use of Video and Audio Texts in EFL Listening Test

    Science.gov (United States)

    Basal, Ahmet; Gülözer, Kaine; Demir, Ibrahim

    2015-01-01

    The study aims to discover whether audio or video modality in a listening test is more beneficial to test takers. In this study, the posttest-only control group design was utilized and quantitative data were collected in order to measure participant performances concerning two types of modality (audio or video) in a listening test. The…

  17. Effect of Audio vs. Video on Aural Discrimination of Vowels

    Science.gov (United States)

    McCrocklin, Shannon

    2012-01-01

    Despite the growing use of media in the classroom, the effects of using of audio versus video in pronunciation teaching has been largely ignored. To analyze the impact of the use of audio or video training on aural discrimination of vowels, 61 participants (all students at a large American university) took a pre-test followed by two training…

  18. A Case Study on Audio Feedback with Geography Undergraduates

    Science.gov (United States)

    Rodway-Dyer, Sue; Knight, Jasper; Dunne, Elizabeth

    2011-01-01

    Several small-scale studies have suggested that audio feedback can help students to reflect on their learning and to develop deep learning approaches that are associated with higher attainment in assessments. For this case study, Geography undergraduates were given audio feedback on a written essay assignment, alongside traditional written…

  19. Automated Speech and Audio Analysis for Semantic Access to Multimedia

    NARCIS (Netherlands)

    Jong, F.M.G. de; Ordelman, R.; Huijbregts, M.

    2006-01-01

    The deployment and integration of audio processing tools can enhance the semantic annotation of multimedia content, and as a consequence, improve the effectiveness of conceptual access tools. This paper overviews the various ways in which automatic speech and audio analysis can contribute to

  20. Decision-level fusion for audio-visual laughter detection

    NARCIS (Netherlands)

    Reuderink, B.; Poel, M.; Truong, K.; Poppe, R.; Pantic, M.

    2008-01-01

    Laughter is a highly variable signal, which can be caused by a spectrum of emotions. This makes the automatic detection of laughter a challenging, but interesting task. We perform automatic laughter detection using audio-visual data from the AMI Meeting Corpus. Audio-visual laughter detection is

  1. Automated speech and audio analysis for semantic access to multimedia

    NARCIS (Netherlands)

    de Jong, Franciska M.G.; Ordelman, Roeland J.F.; Huijbregts, M.A.H.; Avrithis, Y.; Kompatsiaris, Y.; Staab, S.; O' Connor, N.E.

    2006-01-01

    The deployment and integration of audio processing tools can enhance the semantic annotation of multimedia content, and as a consequence, improve the effectiveness of conceptual access tools. This paper overviews the various ways in which automatic speech and audio analysis can contribute to

  2. On the Use of Memory Models in Audio Features

    DEFF Research Database (Denmark)

    Jensen, Karl Kristoffer

    2011-01-01

    Audio feature estimation is potentially improved by including higher- level models. One such model is the Short Term Memory (STM) model. A new paradigm of audio feature estimation is obtained by adding the influence of notes in the STM. These notes are identified when the perceptual spectral flux......, and an initial experiment with sensory dissonance has been undertaken with good results....

  3. Automatic processing of CERN video, audio and photo archives

    CERN Document Server

    Kwiatek, M

    2008-01-01

    The digitalization of CERN audio-visual archives, a major task currently in progress, will generate over 40 TB of video, audio and photo files. Storing these files is one issue, but a far more important challenge is to provide long-time coherence of the archive and to make these files available on-line with minimum manpower investment.

  4. Improving audio chord transcription by exploiting harmonic and metric knowledge

    NARCIS (Netherlands)

    de Haas, W.B.; Rodrigues Magalhães, J.P.; Wiering, F.

    2012-01-01

    We present a new system for chord transcription from polyphonic musical audio that uses domain-specific knowledge about tonal harmony and metrical position to improve chord transcription performance. Low-level pulse and spectral features are extracted from an audio source using the Vamp plugin

  5. PROTOTIPE KOMPRESI LOSSLESS AUDIO CODEC MENGGUNAKAN ENTROPY ENCODING

    OpenAIRE

    Andreas Soegandi

    2010-01-01

    The purpose of this study was to perform lossless compression on the uncompress audio file audio to minimize file size without reducing the quality. The application is developed using the entropy encoding compression method with rice coding technique. For the result, the compression ratio is good enough and easy to be developed because the algorithm is quite simple. 

  6. Prototipe Kompresi Lossless Audio Codec Menggunakan Entropy Encoding

    Directory of Open Access Journals (Sweden)

    Andreas Soegandi

    2010-12-01

    Full Text Available The purpose of this study was to perform lossless compression on the uncompress audio file audio to minimize file size without reducing the quality. The application is developed using the entropy encoding compression method with rice coding technique. For the result, the compression ratio is good enough and easy to be developed because the algorithm is quite simple. 

  7. Evaluation of Audio Books: A Guide for Teachers.

    Science.gov (United States)

    Brown, Jean E.

    2003-01-01

    Considers how as educators recognize the importance of improving listening skills among students, the role of audio books gains curricular significance. Notes that teachers can use them for whole class work, or for students to work in small groups, or individually. Presents a guide for evaluating audio books. (SG)

  8. Some Characteristics of Audio Description and the Corresponding Moving Image.

    Science.gov (United States)

    Turner, James M.

    1998-01-01

    This research is concerned with reusing texts produced by audio describers as a source for automatically deriving shot-level indexing for film and video products. Results reinforce the notion that audio description is not sufficient on its own as a source for generating an index to the image, but it is valuable because it describes what is going…

  9. Multilevel inverter based class D audio amplifier for capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    The reduced semiconductor voltage stress makes the multilevel inverters especially interesting, when driving capacitive transducers for audio applications. A ± 300 V flying capacitor class D audio amplifier driving a 100 nF load in the midrange region of 0.1-3.5 kHz with Total Harmonic Distortion...... plus Noise (THD+N) belo w1%is presented....

  10. Tonal description of music audio signals

    OpenAIRE

    Gómez Gutiérrez, Emilia

    2006-01-01

    Aquesta tesi doctoral proposa i avalua un enfocament computacional per a la descripció automàtica dels aspectes tonals de la música a partir de l'anàlisi de senyals d'-audio polifòniques. Aquests mètodes es centren en el càlcul de descriptors de distribucions de notes, en l'estimació de tonalitat d'una peça, en la visualització de l'evolució del centre tonal o en la mesura de la similitud tonal entre dues peces diferents. Aquesta tesi contribueix substancialment al camp de la descripció tonal...

  11. Audio visual information materials for risk communication

    International Nuclear Information System (INIS)

    Gunji, Ikuko; Tabata, Rimiko; Ohuchi, Naomi

    2005-07-01

    Japan Nuclear Cycle Development Institute (JNC), Tokai Works set up the Risk Communication Study Team in January, 2001 to promote mutual understanding between the local residents and JNC. The Team has studied risk communication from various viewpoints and developed new methods of public relations which are useful for the local residents' risk perception toward nuclear issues. We aim to develop more effective risk communication which promotes a better mutual understanding of the local residents, by providing the risk information of the nuclear fuel facilities such a Reprocessing Plant and other research and development facilities. We explain the development process of audio visual information materials which describe our actual activities and devices for the risk management in nuclear fuel facilities, and our discussion through the effectiveness measurement. (author)

  12. AUDIO CRYPTANALYSIS- AN APPLICATION OF SYMMETRIC KEY CRYPTOGRAPHY AND AUDIO STEGANOGRAPHY

    Directory of Open Access Journals (Sweden)

    Smita Paira

    2016-09-01

    Full Text Available In the recent trend of network and technology, “Cryptography” and “Steganography” have emerged out as the essential elements of providing network security. Although Cryptography plays a major role in the fabrication and modification of the secret message into an encrypted version yet it has certain drawbacks. Steganography is the art that meets one of the basic limitations of Cryptography. In this paper, a new algorithm has been proposed based on both Symmetric Key Cryptography and Audio Steganography. The combination of a randomly generated Symmetric Key along with LSB technique of Audio Steganography sends a secret message unrecognizable through an insecure medium. The Stego File generated is almost lossless giving a 100 percent recovery of the original message. This paper also presents a detailed experimental analysis of the algorithm with a brief comparison with other existing algorithms and a future scope. The experimental verification and security issues are promising.

  13. Dynamic Bayesian Networks for Audio-Visual Speech Recognition

    Directory of Open Access Journals (Sweden)

    Liang Luhong

    2002-01-01

    Full Text Available The use of visual features in audio-visual speech recognition (AVSR is justified by both the speech generation mechanism, which is essentially bimodal in audio and visual representation, and by the need for features that are invariant to acoustic noise perturbation. As a result, current AVSR systems demonstrate significant accuracy improvements in environments affected by acoustic noise. In this paper, we describe the use of two statistical models for audio-visual integration, the coupled HMM (CHMM and the factorial HMM (FHMM, and compare the performance of these models with the existing models used in speaker dependent audio-visual isolated word recognition. The statistical properties of both the CHMM and FHMM allow to model the state asynchrony of the audio and visual observation sequences while preserving their natural correlation over time. In our experiments, the CHMM performs best overall, outperforming all the existing models and the FHMM.

  14. High-Order Sparse Linear Predictors for Audio Processing

    DEFF Research Database (Denmark)

    Giacobello, Daniele; van Waterschoot, Toon; Christensen, Mads Græsbøll

    2010-01-01

    Linear prediction has generally failed to make a breakthrough in audio processing, as it has done in speech processing. This is mostly due to its poor modeling performance, since an audio signal is usually an ensemble of different sources. Nevertheless, linear prediction comes with a whole set...... of interesting features that make the idea of using it in audio processing not far fetched, e.g., the strong ability of modeling the spectral peaks that play a dominant role in perception. In this paper, we provide some preliminary conjectures and experiments on the use of high-order sparse linear predictors...... in audio processing. These predictors, successfully implemented in modeling the short-term and long-term redundancies present in speech signals, will be used to model tonal audio signals, both monophonic and polyphonic. We will show how the sparse predictors are able to model efficiently the different...

  15. Object-based audio reproduction and the audio scene description format

    OpenAIRE

    Geier, Matthias; Ahrens, Jens; Spors, Sascha

    2010-01-01

    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich. This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. The introduction of new techniques for audio reproduction such as HRTF-based technology, wave field synthesis and higher-order Ambisonics is accompanied by a paradigm shift ...

  16. Electrophysiological evidence for Audio-visuo-lingual speech integration.

    Science.gov (United States)

    Treille, Avril; Vilain, Coriandre; Schwartz, Jean-Luc; Hueber, Thomas; Sato, Marc

    2018-01-31

    Recent neurophysiological studies demonstrate that audio-visual speech integration partly operates through temporal expectations and speech-specific predictions. From these results, one common view is that the binding of auditory and visual, lipread, speech cues relies on their joint probability and prior associative audio-visual experience. The present EEG study examined whether visual tongue movements integrate with relevant speech sounds, despite little associative audio-visual experience between the two modalities. A second objective was to determine possible similarities and differences of audio-visual speech integration between unusual audio-visuo-lingual and classical audio-visuo-labial modalities. To this aim, participants were presented with auditory, visual, and audio-visual isolated syllables, with the visual presentation related to either a sagittal view of the tongue movements or a facial view of the lip movements of a speaker, with lingual and facial movements previously recorded by an ultrasound imaging system and a video camera. In line with previous EEG studies, our results revealed an amplitude decrease and a latency facilitation of P2 auditory evoked potentials in both audio-visual-lingual and audio-visuo-labial conditions compared to the sum of unimodal conditions. These results argue against the view that auditory and visual speech cues solely integrate based on prior associative audio-visual perceptual experience. Rather, they suggest that dynamic and phonetic informational cues are sharable across sensory modalities, possibly through a cross-modal transfer of implicit articulatory motor knowledge. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Perceived Audio Quality Analysis in Digital Audio Broadcasting Plus System Based on PEAQ

    Directory of Open Access Journals (Sweden)

    K. Ulovec

    2018-04-01

    Full Text Available Broadcasters need to decide on bitrates of the services in the multiplex transmitted via Digital Audio Broadcasting Plus system. The bitrate should be set as low as possible for maximal number of services, but with high quality, not lower than in conventional analog systems. In this paper, the objective method Perceptual Evaluation of Audio Quality is used to analyze the perceived audio quality for appropriate codecs --- MP2 and AAC offering three profiles. The main aim is to determine dependencies on the type of signal --- music and speech, the number of channels --- stereo and mono, and the bitrate. Results indicate that only MP2 codec and AAC Low Complexity profile reach imperceptible quality loss. The MP2 codec needs higher bitrate than AAC Low Complexity profile for the same quality. For the both versions of AAC High-Efficiency profiles, the limit bitrates are determined above which less complex profiles outperform the more complex ones and higher bitrates above these limits are not worth using. It is shown that stereo music has worse quality than stereo speech generally, whereas for mono, the dependencies vary upon the codec/profile. Furthermore, numbers of services satisfying various quality criteria are presented.

  18. Subjective and Objective Assessment of Perceived Audio Quality of Current Digital Audio Broadcasting Systems and Web-Casting Applications

    NARCIS (Netherlands)

    Pocta, P.; Beerends, J.G.

    2015-01-01

    This paper investigates the impact of different audio codecs typically deployed in current digital audio broadcasting (DAB) systems and web-casting applications, which represent a main source of quality impairment in these systems and applications, on the quality perceived by the end user. Both

  19. Horatio Audio-Describes Shakespeare's "Hamlet": Blind and Low-Vision Theatre-Goers Evaluate an Unconventional Audio Description Strategy

    Science.gov (United States)

    Udo, J. P.; Acevedo, B.; Fels, D. I.

    2010-01-01

    Audio description (AD) has been introduced as one solution for providing people who are blind or have low vision with access to live theatre, film and television content. However, there is little research to inform the process, user preferences and presentation style. We present a study of a single live audio-described performance of Hart House…

  20. Portable audio electronics for impedance-based measurements in microfluidics

    International Nuclear Information System (INIS)

    Wood, Paul; Sinton, David

    2010-01-01

    We demonstrate the use of audio electronics-based signals to perform on-chip electrochemical measurements. Cell phones and portable music players are examples of consumer electronics that are easily operated and are ubiquitous worldwide. Audio output (play) and input (record) signals are voltage based and contain frequency and amplitude information. A cell phone, laptop soundcard and two compact audio players are compared with respect to frequency response; the laptop soundcard provides the most uniform frequency response, while the cell phone performance is found to be insufficient. The audio signals in the common portable music players and laptop soundcard operate in the range of 20 Hz to 20 kHz and are found to be applicable, as voltage input and output signals, to impedance-based electrochemical measurements in microfluidic systems. Validated impedance-based measurements of concentration (0.1–50 mM), flow rate (2–120 µL min −1 ) and particle detection (32 µm diameter) are demonstrated. The prevailing, lossless, wave audio file format is found to be suitable for data transmission to and from external sources, such as a centralized lab, and the cost of all hardware (in addition to audio devices) is ∼10 USD. The utility demonstrated here, in combination with the ubiquitous nature of portable audio electronics, presents new opportunities for impedance-based measurements in portable microfluidic systems. (technical note)

  1. An inconclusive digital audio authenticity examination: a unique case.

    Science.gov (United States)

    Koenig, Bruce E; Lacey, Douglas S

    2012-01-01

    This case report sets forth an authenticity examination of 35 encrypted, proprietary-format digital audio files containing recorded telephone conversations between two codefendants in a criminal matter. The codefendant who recorded the conversations did so on a recording system he developed; additionally, he was both a forensic audio authenticity examiner, who had published and presented in the field, and was the head of a professional audio society's writing group for authenticity standards. The authors conducted the examination of the recordings following nine laboratory steps of the peer-reviewed and published 11-step digital audio authenticity protocol. Based considerably on the codefendant's direct involvement with the development of the encrypted audio format, his experience in the field of forensic audio authenticity analysis, and the ease with which the audio files could be accessed, converted, edited in the gap areas, and reconstructed in such a way that the processes were undetected, the authors concluded that the recordings could not be scientifically authenticated through accepted forensic practices. © 2011 American Academy of Forensic Sciences.

  2. Music Genre Classification Using MIDI and Audio Features

    Science.gov (United States)

    Cataltepe, Zehra; Yaslan, Yusuf; Sonmez, Abdullah

    2007-12-01

    We report our findings on using MIDI files and audio features from MIDI, separately and combined together, for MIDI music genre classification. We use McKay and Fujinaga's 3-root and 9-leaf genre data set. In order to compute distances between MIDI pieces, we use normalized compression distance (NCD). NCD uses the compressed length of a string as an approximation to its Kolmogorov complexity and has previously been used for music genre and composer clustering. We convert the MIDI pieces to audio and then use the audio features to train different classifiers. MIDI and audio from MIDI classifiers alone achieve much smaller accuracies than those reported by McKay and Fujinaga who used not NCD but a number of domain-based MIDI features for their classification. Combining MIDI and audio from MIDI classifiers improves accuracy and gets closer to, but still worse, accuracies than McKay and Fujinaga's. The best root genre accuracies achieved using MIDI, audio, and combination of them are 0.75, 0.86, and 0.93, respectively, compared to 0.98 of McKay and Fujinaga. Successful classifier combination requires diversity of the base classifiers. We achieve diversity through using certain number of seconds of the MIDI file, different sample rates and sizes for the audio file, and different classification algorithms.

  3. Music Genre Classification Using MIDI and Audio Features

    Directory of Open Access Journals (Sweden)

    Abdullah Sonmez

    2007-01-01

    Full Text Available We report our findings on using MIDI files and audio features from MIDI, separately and combined together, for MIDI music genre classification. We use McKay and Fujinaga's 3-root and 9-leaf genre data set. In order to compute distances between MIDI pieces, we use normalized compression distance (NCD. NCD uses the compressed length of a string as an approximation to its Kolmogorov complexity and has previously been used for music genre and composer clustering. We convert the MIDI pieces to audio and then use the audio features to train different classifiers. MIDI and audio from MIDI classifiers alone achieve much smaller accuracies than those reported by McKay and Fujinaga who used not NCD but a number of domain-based MIDI features for their classification. Combining MIDI and audio from MIDI classifiers improves accuracy and gets closer to, but still worse, accuracies than McKay and Fujinaga's. The best root genre accuracies achieved using MIDI, audio, and combination of them are 0.75, 0.86, and 0.93, respectively, compared to 0.98 of McKay and Fujinaga. Successful classifier combination requires diversity of the base classifiers. We achieve diversity through using certain number of seconds of the MIDI file, different sample rates and sizes for the audio file, and different classification algorithms.

  4. Quality Enhancement of Compressed Audio Based on Statistical Conversion

    Directory of Open Access Journals (Sweden)

    Mouchtaris Athanasios

    2008-01-01

    Full Text Available Most audio compression formats are based on the idea of low bit rate transparent encoding. As these types of audio signals are starting to migrate from portable players with inexpensive headphones to higher quality home audio systems, it is becoming evident that higher bit rates may be required to maintain transparency. We propose a novel method that enhances low bit rate encoded audio segments by applying multiband audio resynthesis methods in a postprocessing stage. Our algorithm employs the highly flexible Generalized Gaussian mixture model which offers a more accurate representation of audio features than the Gaussian mixture model. A novel residual conversion technique is applied which proves to significantly improve the enhancement performance without excessive overhead. In addition, both cepstral and residual errors are dramatically decreased by a feature-alignment scheme that employs a sorting transformation. Some improvements regarding the quantization step are also described that enable us to further reduce the algorithm overhead. Signal enhancement examples are presented and the results show that the overhead size incurred by the algorithm is a fraction of the uncompressed signal size. Our results show that the resulting audio quality is comparable to that of a standard perceptual codec operating at approximately the same bit rate.

  5. Quality Enhancement of Compressed Audio Based on Statistical Conversion

    Directory of Open Access Journals (Sweden)

    Chris Kyriakakis

    2008-07-01

    Full Text Available Most audio compression formats are based on the idea of low bit rate transparent encoding. As these types of audio signals are starting to migrate from portable players with inexpensive headphones to higher quality home audio systems, it is becoming evident that higher bit rates may be required to maintain transparency. We propose a novel method that enhances low bit rate encoded audio segments by applying multiband audio resynthesis methods in a postprocessing stage. Our algorithm employs the highly flexible Generalized Gaussian mixture model which offers a more accurate representation of audio features than the Gaussian mixture model. A novel residual conversion technique is applied which proves to significantly improve the enhancement performance without excessive overhead. In addition, both cepstral and residual errors are dramatically decreased by a feature-alignment scheme that employs a sorting transformation. Some improvements regarding the quantization step are also described that enable us to further reduce the algorithm overhead. Signal enhancement examples are presented and the results show that the overhead size incurred by the algorithm is a fraction of the uncompressed signal size. Our results show that the resulting audio quality is comparable to that of a standard perceptual codec operating at approximately the same bit rate.

  6. Optimized Audio Classification and Segmentation Algorithm by Using Ensemble Methods

    Directory of Open Access Journals (Sweden)

    Saadia Zahid

    2015-01-01

    Full Text Available Audio segmentation is a basis for multimedia content analysis which is the most important and widely used application nowadays. An optimized audio classification and segmentation algorithm is presented in this paper that segments a superimposed audio stream on the basis of its content into four main audio types: pure-speech, music, environment sound, and silence. An algorithm is proposed that preserves important audio content and reduces the misclassification rate without using large amount of training data, which handles noise and is suitable for use for real-time applications. Noise in an audio stream is segmented out as environment sound. A hybrid classification approach is used, bagged support vector machines (SVMs with artificial neural networks (ANNs. Audio stream is classified, firstly, into speech and nonspeech segment by using bagged support vector machines; nonspeech segment is further classified into music and environment sound by using artificial neural networks and lastly, speech segment is classified into silence and pure-speech segments on the basis of rule-based classifier. Minimum data is used for training classifier; ensemble methods are used for minimizing misclassification rate and approximately 98% accurate segments are obtained. A fast and efficient algorithm is designed that can be used with real-time multimedia applications.

  7. MPEG-4 low-delay general audio coding

    Science.gov (United States)

    Sporer, Thomas; Grill, Bernhard; Herre, Juergen

    2001-07-01

    Traditionally, speech coding for communication purposes and perceptual audio coding have been separate worlds. On one hand, speech coders provide acceptable speech quality at very low data rates and low delays which are suitable for two-way communication applications, such as Voice over IP (VoIP) or teleconferencing. Due to the underlying coding paradigm, however, such coders do not perform well for non-speech signals (e.g.~music and environmental noise). Furthermore, the sound quality and naturalness is severely limited by the fact that most coders are working in narrow-band mode, i.e. with a bandwidth below 4 kHz. On the other hand, perceptual audio codecs provide excellent subjective audio quality for a broad range of signals including speech at bit rates down to 16 kbit/s. The delay of such a coder/decoder chain, however, usually exceeds 200 ms at very low data rates and in this way is not acceptable for interactive two-way communication. This paper describes a coding scheme which is designed to combine the advantages of perceptual audio coding with the low delay necessary for two-way communication. The codec was standardized within MPEG-4 Version 2 Audio under the work item ``Low Delay Audio Coding'' and is derived from the ISO/MPEG-2/4 Advanced Audio Coding (AAC) algorithm. The algorithm provides modes operating at algorithmic delay as low as 20 ms and is equipped to handle all full-bandwidth high-quality audio signals, both in monophonic, stereophonic and even multi-channel format. Despite of the low algorithmic delay, the codec delivers better audio quality than MPEG-1 Layer-3 (MP3) at the same bit rate. The paper also addresses issues pertaining to the integration of the coder into H.32x and SDP applications.

  8. Power

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2016-01-01

    In this chapter, we will explore the dynamics of power in processes of creativity, and show its paradoxical nature as both a bridge and a barrier to creativity in organisations. Recent social psychological experimental research (Slighte, de Dreu & Nijstad, 2011) on the relation between power...... and floating source for empowering people in the organisation. We will explore and discuss here the potentials, challenges and pitfalls of power in relation to creativity in the life of organisations today. The aim is to demonstrate that power struggles may be utilised as constructive sources of creativity...

  9. Survey of compressed domain audio features and their expressiveness

    Science.gov (United States)

    Pfeiffer, Silvia; Vincent, Thomas

    2003-01-01

    We give an overview of existing audio analysis approaches in the compressed domain and incorporate them into a coherent formal structure. After examining the kinds of information accessible in an MPEG-1 compressed audio stream, we describe a coherent approach to determine features from them and report on a number of applications they enable. Most of them aim at creating an index to the audio stream by segmenting the stream into temporally coherent regions, which may be classified into pre-specified types of sounds such as music, speech, speakers, animal sounds, sound effects, or silence. Other applications centre around sound recognition such as gender, beat or speech recognition.

  10. A review of lossless audio compression standards and algorithms

    Science.gov (United States)

    Muin, Fathiah Abdul; Gunawan, Teddy Surya; Kartiwi, Mira; Elsheikh, Elsheikh M. A.

    2017-09-01

    Over the years, lossless audio compression has gained popularity as researchers and businesses has become more aware of the need for better quality and higher storage demand. This paper will analyse various lossless audio coding algorithm and standards that are used and available in the market focusing on Linear Predictive Coding (LPC) specifically due to its popularity and robustness in audio compression, nevertheless other prediction methods are compared to verify this. Advanced representation of LPC such as LSP decomposition techniques are also discussed within this paper.

  11. Robustness evaluation of transactional audio watermarking systems

    Science.gov (United States)

    Neubauer, Christian; Steinebach, Martin; Siebenhaar, Frank; Pickel, Joerg

    2003-06-01

    Distribution via Internet is of increasing importance. Easy access, transmission and consumption of digitally represented music is very attractive to the consumer but led also directly to an increasing problem of illegal copying. To cope with this problem watermarking is a promising concept since it provides a useful mechanism to track illicit copies by persistently attaching property rights information to the material. Especially for online music distribution the use of so-called transaction watermarking, also denoted with the term bitstream watermarking, is beneficial since it offers the opportunity to embed watermarks directly into perceptually encoded material without the need of full decompression/compression. Besides the concept of bitstream watermarking, former publications presented the complexity, the audio quality and the detection performance. These results are now extended by an assessment of the robustness of such schemes. The detection performance before and after applying selected attacks is presented for MPEG-1/2 Layer 3 (MP3) and MPEG-2/4 AAC bitstream watermarking, contrasted to the performance of PCM spread spectrum watermarking.

  12. Analysis of musical expression in audio signals

    Science.gov (United States)

    Dixon, Simon

    2003-01-01

    In western art music, composers communicate their work to performers via a standard notation which specificies the musical pitches and relative timings of notes. This notation may also include some higher level information such as variations in the dynamics, tempo and timing. Famous performers are characterised by their expressive interpretation, the ability to convey structural and emotive information within the given framework. The majority of work on audio content analysis focusses on retrieving score-level information; this paper reports on the extraction of parameters describing the performance, a task which requires a much higher degree of accuracy. Two systems are presented: BeatRoot, an off-line beat tracking system which finds the times of musical beats and tracks changes in tempo throughout a performance, and the Performance Worm, a system which provides a real-time visualisation of the two most important expressive dimensions, tempo and dynamics. Both of these systems are being used to process data for a large-scale study of musical expression in classical and romantic piano performance, which uses artificial intelligence (machine learning) techniques to discover fundamental patterns or principles governing expressive performance.

  13. Personal audio with a planar bright zone.

    Science.gov (United States)

    Coleman, Philip; Jackson, Philip J B; Olik, Marek; Pedersen, Jan Abildgaard

    2014-10-01

    Reproduction of multiple sound zones, in which personal audio programs may be consumed without the need for headphones, is an active topic in acoustical signal processing. Many approaches to sound zone reproduction do not consider control of the bright zone phase, which may lead to self-cancellation problems if the loudspeakers surround the zones. Conversely, control of the phase in a least-squares sense comes at a cost of decreased level difference between the zones and frequency range of cancellation. Single-zone approaches have considered plane wave reproduction by focusing the sound energy in to a point in the wavenumber domain. In this article, a planar bright zone is reproduced via planarity control, which constrains the bright zone energy to impinge from a narrow range of angles via projection in to a spatial domain. Simulation results using a circular array surrounding two zones show the method to produce superior contrast to the least-squares approach, and superior planarity to the contrast maximization approach. Practical performance measurements obtained in an acoustically treated room verify the conclusions drawn under free-field conditions.

  14. Simple PWM modulator topology with excellent dynamic behavior

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    This paper proposes a new PWM modulator topology. The modulator is used in switch mode audio power amplifiers, but the topology can be used in a wide range of applications. Due to excellent transient behavior, the modulator is very suited for VRMs or other types of DC-DC or DC-AC applications....

  15. Pulse-width modulated DC-DC power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2008-01-01

    This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,

  16. Advances in audio watermarking based on singular value decomposition

    CERN Document Server

    Dhar, Pranab Kumar

    2015-01-01

    This book introduces audio watermarking methods for copyright protection, which has drawn extensive attention for securing digital data from unauthorized copying. The book is divided into two parts. First, an audio watermarking method in discrete wavelet transform (DWT) and discrete cosine transform (DCT) domains using singular value decomposition (SVD) and quantization is introduced. This method is robust against various attacks and provides good imperceptible watermarked sounds. Then, an audio watermarking method in fast Fourier transform (FFT) domain using SVD and Cartesian-polar transformation (CPT) is presented. This method has high imperceptibility and high data payload and it provides good robustness against various attacks. These techniques allow media owners to protect copyright and to show authenticity and ownership of their material in a variety of applications.   ·         Features new methods of audio watermarking for copyright protection and ownership protection ·         Outl...

  17. Audio-visual temporal perception in children with restored hearing.

    Science.gov (United States)

    Gori, Monica; Chilosi, Anna; Forli, Francesca; Burr, David

    2017-05-01

    It is not clear how audio-visual temporal perception develops in children with restored hearing. In this study we measured temporal discrimination thresholds with an audio-visual temporal bisection task in 9 deaf children with restored audition, and 22 typically hearing children. In typically hearing children, audition was more precise than vision, with no gain in multisensory conditions (as previously reported in Gori et al. (2012b)). However, deaf children with restored audition showed similar thresholds for audio and visual thresholds and some evidence of gain in audio-visual temporal multisensory conditions. Interestingly, we found a strong correlation between auditory weighting of multisensory signals and quality of language: patients who gave more weight to audition had better language skills. Similarly, auditory thresholds for the temporal bisection task were also a good predictor of language skills. This result supports the idea that the temporal auditory processing is associated with language development. Copyright © 2017. Published by Elsevier Ltd.

  18. Can audio recording improve patients' recall of outpatient consultations?

    DEFF Research Database (Denmark)

    Wolderslund, Maiken; Kofoed, Poul-Erik; Axboe, Mette

    Introduction In order to give patients possibility to listen to their consultation again, we have designed a system which gives the patients access to digital audio recordings of their consultations. An Interactive Voice Response platform enables the audio recording and gives the patients access...... to replay their consultation. The intervention is evaluated in a randomised controlled trial with 5.460 patients in order to determine whether providing patients with digital audio recording of the consultation affects the patients overall perception of their consultation. In addition to this primary...... objective we want to investigate if replay of the consultations improves the patients’ recall of the information given. Methods Interviews are carried out with 40 patients whose consultations have been audio recorded. Patients are divided into two groups, those who have listened to their consultation...

  19. Behavioral Science Design for Audio-Visual Software Development

    Science.gov (United States)

    Foster, Dennis L.

    1974-01-01

    A discussion of the basic structure of the behavioral audio-visual production which consists of objectives analysis, approach determination, technical production, fulfillment evaluation, program refinement, implementation, and follow-up. (Author)

  20. Perancangan Sistem Audio Mobil Berbasiskan Sistem Pakar dan Web

    Directory of Open Access Journals (Sweden)

    Djunaidi Santoso

    2011-12-01

    Full Text Available Designing car audio that fits user’s needs is a fun activity. However, the design often consumes more time and costly since it should be consulted to the experts several times. For easy access to information in designing a car audio system as well as error prevention, an car audio system based on expert system and web is designed for those who do not have sufficient time and expense to consult directly to experts. This system consists of tutorial modules designed using the HyperText Preprocessor (PHP and MySQL as database. This car audio system design is evaluated uses black box testing method which focuses on the functional needs of the application. Tests are performed by providing inputs and produce outputs corresponding to the function of each module. The test results prove the correspondence between input and output, which means that the program meet the initial goals of the design. 

  1. Audio CAPTCHA for SIP-Based VoIP

    Science.gov (United States)

    Soupionis, Yannis; Tountas, George; Gritzalis, Dimitris

    Voice over IP (VoIP) introduces new ways of communication, while utilizing existing data networks to provide inexpensive voice communications worldwide as a promising alternative to the traditional PSTN telephony. SPam over Internet Telephony (SPIT) is one potential source of future annoyance in VoIP. A common way to launch a SPIT attack is the use of an automated procedure (bot), which generates calls and produces audio advertisements. In this paper, our goal is to design appropriate CAPTCHA to fight such bots. We focus on and develop audio CAPTCHA, as the audio format is more suitable for VoIP environments and we implement it in a SIP-based VoIP environment. Furthermore, we suggest and evaluate the specific attributes that audio CAPTCHA should incorporate in order to be effective, and test it against an open source bot implementation.

  2. Effectiveness of 3-D audio for warnings in the cockpit

    NARCIS (Netherlands)

    Oving, A.B.; Veltman, J.A.; Bronkhorst, A.W.

    2004-01-01

    Een tweetal vliegsimulator experimenten lieten zien dat piloten sneller reagereerden op de auditieve waarschuwingen van het TCAS systeem in de civiele cockpit, waneer deze waarschuwingen werden gepresenteerd met 3D-audio in vergelijking tot mono geluid.

  3. PENGEMBANGAN MEDIA AUDIO VISUAL PEMBELAJARAN MENULIS BERITA SINGKAT

    OpenAIRE

    Sastri, Sastri; Wiryotinoyo, Mujiyono; Sudaryono, Sudaryono

    2015-01-01

    This article is based on a developmental research which is aimed at constructing audio visual media writing news. This media is developed with a contextual approach. Materials and training tasks are presented, designed using contextual approach or match an environment of student. Through this approach, students are expected to construct experiences into the learning situation. The design used in the development of audio-visual media using the model of learning to write news Alessi and Trollip...

  4. El Digital Audio Tape Recorder. Contra autores y creadores

    Directory of Open Access Journals (Sweden)

    Jun Ono

    2015-01-01

    Full Text Available La llamada "DAT" (abreviatura por "digital audio tape recorder" / grabadora digital de audio ha recibido cobertura durante mucho tiempo en los medios masivos de Japón y otros países, como un producto acústico electrónico nuevo y controversial de la industria japonesa de artefactos electrónicos. ¿Qué ha pasado con el objeto de esta controversia?

  5. [Development of Audio Indicator System for Respiratory Dynamic CT Imaging].

    Science.gov (United States)

    Muramatsu, Shun; Moriya, Hiroshi; Tsukagoshi, Shinsuke; Yamada, Norikazu

    We created the device, which can conduct a radiological technologist's voice to a subject during CT scanning. For 149 lung cancer, dynamic respiratory CT were performed. 92 cases were performed using this device, the others were without this device. The respiratory cycle and respiratory amplitude were analyzed from the lung density. A stable respirating cycle was obtained by using the audio indicator system. The audio indicator system is useful for respiratory dynamic CT.

  6. Automated processing of massive audio/video content using FFmpeg

    Directory of Open Access Journals (Sweden)

    Kia Siang Hock

    2014-01-01

    Full Text Available Audio and video content forms an integral, important and expanding part of the digital collections in libraries and archives world-wide. While these memory institutions are familiar and well-versed in the management of more conventional materials such as books, periodicals, ephemera and images, the handling of audio (e.g., oral history recordings and video content (e.g., audio-visual recordings, broadcast content requires additional toolkits. In particular, a robust and comprehensive tool that provides a programmable interface is indispensable when dealing with tens of thousands of hours of audio and video content. FFmpeg is comprehensive and well-established open source software that is capable of the full-range of audio/video processing tasks (such as encode, decode, transcode, mux, demux, stream and filter. It is also capable of handling a wide-range of audio and video formats, a unique challenge in memory institutions. It comes with a command line interface, as well as a set of developer libraries that can be incorporated into applications.

  7. Depth perception of audio sources in stereo 3D environments

    Science.gov (United States)

    Corrigan, David; Gorzel, Marcin; Squires, John; Boland, Frank

    2013-03-01

    In this paper we undertook perceptual experiments to determine the allowed differences in depth between audio and visual stimuli in stereoscopic-3D environments while being perceived as congruent. We also investigated whether the nature of the environment and stimuli affects the perception of congruence. This was achieved by creating an audio-visual environment consisting of a photorealistic visual environment captured by a camera under orthostereoscopic conditions and a virtual audio environment generated by measuring the acoustic properties of the real environment. The visual environment consisted of a room with a loudspeaker or person forming the visual stimulus and was presented to the viewer using a passive stereoscopic display. Pink noise samples and female speech were used as audio stimuli which were presented over headphones using binaural renderings. The stimuli were generated at different depths from the viewer and the viewer was asked to determine whether the audio stimulus was nearer, further away or at the same depth as the visual stimulus. From our experiments it is shown that there is a significant range of depth differences for which audio and visual stimuli are perceived as congruent. Furthermore, this range increases as the depth of the visual stimulus increases.

  8. Communicative Competence in Audio Classrooms: A Position Paper for the CADE 1991 Conference.

    Science.gov (United States)

    Burge, Liz

    Classroom practitioners need to move their attention away from the technological and logistical competencies required for audio conferencing (AC) to the required communicative competencies in order to advance their skills in handling the psychodynamics of audio virtual classrooms which include audio alone and audio with graphics. While the…

  9. TNO at TRECVID 2008, Combining Audio and Video Fingerprinting for Robust Copy Detection

    NARCIS (Netherlands)

    Doets, P.J.; Eendebak, P.T.; Ranguelova, E.; Kraaij, W.

    2009-01-01

    TNO has evaluated a baseline audio and a video fingerprinting system based on robust hashing for the TRECVID 2008 copy detection task. We participated in the audio, the video and the combined audio-video copy detection task. The audio fingerprinting implementation clearly outperformed the video

  10. 37 CFR 201.27 - Initial notice of distribution of digital audio recording devices or media.

    Science.gov (United States)

    2010-07-01

    ... distribution of digital audio recording devices or media. 201.27 Section 201.27 Patents, Trademarks, and... Initial notice of distribution of digital audio recording devices or media. (a) General. This section..., any digital audio recording device or digital audio recording medium in the United States. (b...

  11. Design and development of power supplies at VECC for accelerators

    International Nuclear Information System (INIS)

    Thakur, S.K.

    2013-01-01

    Several power supplies have been designed and developed in-house incorporating various topologies to match the load requirements. Most of the power supplies have been being utilised in K-130 and K-500 cyclotrons operation successfully from last several years. Amongst other types, Switching Mode PS (SMPS), Phase Controlled Rectifier (PCR), Linear mode power supply are mostly in use, irrespective of their own merits and demerits. Switching mode power supply (SMPS) is most common topology for various applications ranging from high current to high voltage applications. Due to low stored energy and faster response, the SMPS incorporating Pulse Switch Modulation (PSM) configuration is most suitable for high voltage DC power supply at larger power compared to its counterparts, makes possible to operate the power system without crowbar. For an IOT cathode power supply, a 200kW at - 40kV High voltage power supply is under development incorporating SMPS and PSM technique. Earlier, High Voltage power supply was made by using Tetrode Tube in linear mode for RF amplifier for K-130 Cyclotron. Later, in K-500 Cyclotron, a High Voltage power supply was developed incorporating PCR topology rated at 20kV, 20 Amp for Anodes for 3 nos. of RF amplifiers. These HV power supply is equipped with ultra-fast acting Crowbar Protection System developed in VECC which is for the protection of costly RF Tubes against the internal arc. Design and development of SMPS based Bipolar Power Supply with 4-Quadrant operation rated at ± 27 V, ± 300 Amp with current stability around 100 ppm for Super-conducting Magnets along with quench protection and energy dumping scheme. (author)

  12. High power factor, fixed frequency, three-phase AC/CC converter which uses a single power processing stage; Conversor CA/CC, trifasico, com alto fator de potencia, frequencia fixa, empregando um unico estagio de processamento de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Davila, Jose Gregorio Contreras

    1993-11-01

    This paper introduces a new switching mode power supply with the following properties: zero-voltage switching, pulse-width modulation at constant frequency, three-phase input with power factor and low input current distortion, using a simple power stage. The converter is designed in a manner that the input current harmonic content is reduced naturally. Circuit-operation, theoretical analysis, simulation, design procedure and example are presented. A laboratory prototype rated at 3 kW and operating at 100 Khz, has been fabricated and tested successfully. (author) 15 refs., 75 figs.

  13. Switching power supplies with multiple isolated output and unitary power factor with an only switch; Fonte chaveada com multiplas saidas isoladas e fator de potencia unitario com um unico interruptor

    Energy Technology Data Exchange (ETDEWEB)

    Canesin, Carlos Alberto

    1990-09-01

    The analysis and implementation of switching power supplies with multiple output, through the use of the D C/D C Single Ended Primary Inductance Converter - SEPIC is presented. The structure has a single switch mode processing stage, improved input power factor, with the use of the variable current hysteresis control, or, constant on time control. The analysis of the D C/D C SEPIC, output characteristics and computer simulation is presented. A switching power supply practical design and experimental results are presented to demonstrate the validity of the theoretical analysis. (author)

  14. A simple clockless Network-on-Chip for a commercial audio DSP chip

    DEFF Research Database (Denmark)

    Stensgaard, Mikkel Bystrup; Bjerregaard, Tobias; Sparsø, Jens

    2006-01-01

    to the existing crossbar, it allows all blocks to communicate. The total wire length is decreased by 22% which eases the layout process and makes the design less prone to routing congestion. Not least, the communicating blocks are decoupled by means of the NoC, providing a Globally-Asynchronous, Locally-Synchronous......We design a very small, packet-switched, clockless Network-on-Chip (NoC) as a replacement for the existing crossbar-based communication infrastructure in a commercial audio DSP chip. Both solutions are laid out in a 0.18 um process, and compared in terms of area, power consumption and routing...

  15. Blind Audio Watermarking in Transform Domain Based on Singular Value Decomposition and Exponential-Log Operations

    Directory of Open Access Journals (Sweden)

    P. K. Dhar

    2017-06-01

    Full Text Available Digital watermarking has drawn extensive attention for copyright protection of multimedia data. This paper introduces a blind audio watermarking scheme in discrete cosine transform (DCT domain based on singular value decomposition (SVD, exponential operation (EO, and logarithm operation (LO. In our proposed scheme, initially the original audio is segmented into non-overlapping frames and DCT is applied to each frame. Low frequency DCT coefficients are divided into sub-bands and power of each sub band is calculated. EO is performed on the sub-band with highest power of the DCT coefficients of each frame. SVD is applied to the exponential coefficients of each sub bands with highest power represented in matrix form. Watermark information is embedded into the largest singular value by using a quantization function. Simulation results indicate that the proposed watermarking scheme is highly robust against different attacks. In addition, it has high data payload and shows low error probability rates. Moreover, it provides good performance in terms of imperceptibility, robustness, and data payload compared with some recent state-of-the-art watermarking methods.

  16. Audio Visual Integration with Competing Sources in the Framework of Audio Visual Speech Scene Analysis.

    Science.gov (United States)

    Ganesh, Attigodu Chandrashekara; Berthommier, Frédéric; Schwartz, Jean-Luc

    2016-01-01

    We introduce "Audio-Visual Speech Scene Analysis" (AVSSA) as an extension of the two-stage Auditory Scene Analysis model towards audiovisual scenes made of mixtures of speakers. AVSSA assumes that a coherence index between the auditory and the visual input is computed prior to audiovisual fusion, enabling to determine whether the sensory inputs should be bound together. Previous experiments on the modulation of the McGurk effect by audiovisual coherent vs. incoherent contexts presented before the McGurk target have provided experimental evidence supporting AVSSA. Indeed, incoherent contexts appear to decrease the McGurk effect, suggesting that they produce lower audiovisual coherence hence less audiovisual fusion. The present experiments extend the AVSSA paradigm by creating contexts made of competing audiovisual sources and measuring their effect on McGurk targets. The competing audiovisual sources have respectively a high and a low audiovisual coherence (that is, large vs. small audiovisual comodulations in time). The first experiment involves contexts made of two auditory sources and one video source associated to either the first or the second audio source. It appears that the McGurk effect is smaller after the context made of the visual source associated to the auditory source with less audiovisual coherence. In the second experiment with the same stimuli, the participants are asked to attend to either one or the other source. The data show that the modulation of fusion depends on the attentional focus. Altogether, these two experiments shed light on audiovisual binding, the AVSSA process and the role of attention.

  17. Audio-guided audiovisual data segmentation, indexing, and retrieval

    Science.gov (United States)

    Zhang, Tong; Kuo, C.-C. Jay

    1998-12-01

    While current approaches for video segmentation and indexing are mostly focused on visual information, audio signals may actually play a primary role in video content parsing. In this paper, we present an approach for automatic segmentation, indexing, and retrieval of audiovisual data, based on audio content analysis. The accompanying audio signal of audiovisual data is first segmented and classified into basic types, i.e., speech, music, environmental sound, and silence. This coarse-level segmentation and indexing step is based upon morphological and statistical analysis of several short-term features of the audio signals. Then, environmental sounds are classified into finer classes, such as applause, explosions, bird sounds, etc. This fine-level classification and indexing step is based upon time- frequency analysis of audio signals and the use of the hidden Markov model as the classifier. On top of this archiving scheme, an audiovisual data retrieval system is proposed. Experimental results show that the proposed approach has an accuracy rate higher than 90 percent for the coarse-level classification, and higher than 85 percent for the fine-level classification. Examples of audiovisual data segmentation and retrieval are also provided.

  18. Audio-visual integration through the parallel visual pathways.

    Science.gov (United States)

    Kaposvári, Péter; Csete, Gergő; Bognár, Anna; Csibri, Péter; Tóth, Eszter; Szabó, Nikoletta; Vécsei, László; Sáry, Gyula; Tamás Kincses, Zsigmond

    2015-10-22

    Audio-visual integration has been shown to be present in a wide range of different conditions, some of which are processed through the dorsal, and others through the ventral visual pathway. Whereas neuroimaging studies have revealed integration-related activity in the brain, there has been no imaging study of the possible role of segregated visual streams in audio-visual integration. We set out to determine how the different visual pathways participate in this communication. We investigated how audio-visual integration can be supported through the dorsal and ventral visual pathways during the double flash illusion. Low-contrast and chromatic isoluminant stimuli were used to drive preferably the dorsal and ventral pathways, respectively. In order to identify the anatomical substrates of the audio-visual interaction in the two conditions, the psychophysical results were correlated with the white matter integrity as measured by diffusion tensor imaging.The psychophysiological data revealed a robust double flash illusion in both conditions. A correlation between the psychophysical results and local fractional anisotropy was found in the occipito-parietal white matter in the low-contrast condition, while a similar correlation was found in the infero-temporal white matter in the chromatic isoluminant condition. Our results indicate that both of the parallel visual pathways may play a role in the audio-visual interaction. Copyright © 2015. Published by Elsevier B.V.

  19. The Fungible Audio-Visual Mapping and its Experience

    Directory of Open Access Journals (Sweden)

    Adriana Sa

    2014-12-01

    Full Text Available This article draws a perceptual approach to audio-visual mapping. Clearly perceivable cause and effect relationships can be problematic if one desires the audience to experience the music. Indeed perception would bias those sonic qualities that fit previous concepts of causation, subordinating other sonic qualities, which may form the relations between the sounds themselves. The question is, how can an audio-visual mapping produce a sense of causation, and simultaneously confound the actual cause-effect relationships. We call this a fungible audio-visual mapping. Our aim here is to glean its constitution and aspect. We will report a study, which draws upon methods from experimental psychology to inform audio-visual instrument design and composition. The participants are shown several audio-visual mapping prototypes, after which we pose quantitative and qualitative questions regarding their sense of causation, and their sense of understanding the cause-effect relationships. The study shows that a fungible mapping requires both synchronized and seemingly non-related components – sufficient complexity to be confusing. As the specific cause-effect concepts remain inconclusive, the sense of causation embraces the whole. 

  20. A sub-milliwatt audio-processing platform for digital hearing aids

    International Nuclear Information System (INIS)

    Yuan Jia; Chen Liming; Yu Zenghui; Hei Yong

    2014-01-01

    We present a novel audio-processing platform, FlexEngine, which is composed of a 24-bit application-specific instruction-set processor (ASIP) and five dedicated accelerators. Acceleration instructions, compact instructions and repeat instruction are added into the ASIP's instruction set to deal with some core tasks of hearing aid algorithms. The five configurable accelerators are used to execute several of the most common functions of hearing aids. Moreover, several low power strategies, such as clock gating, data isolation, memory partition, bypass mode, sleep mode, are also applied in this platform for power reduction. The proposed platform is implemented in CMOS 130 nm technology, and test results show that power consumption of FlexEngine is 0.863 mW with the clock frequency of 8 MHz at V dd = 1.0 V. (semiconductor integrated circuits)

  1. A sub-milliwatt audio-processing platform for digital hearing aids

    Science.gov (United States)

    Jia, Yuan; Liming, Chen; Zenghui, Yu; Yong, Hei

    2014-07-01

    We present a novel audio-processing platform, FlexEngine, which is composed of a 24-bit application-specific instruction-set processor (ASIP) and five dedicated accelerators. Acceleration instructions, compact instructions and repeat instruction are added into the ASIP's instruction set to deal with some core tasks of hearing aid algorithms. The five configurable accelerators are used to execute several of the most common functions of hearing aids. Moreover, several low power strategies, such as clock gating, data isolation, memory partition, bypass mode, sleep mode, are also applied in this platform for power reduction. The proposed platform is implemented in CMOS 130 nm technology, and test results show that power consumption of FlexEngine is 0.863 mW with the clock frequency of 8 MHz at Vdd = 1.0 V.

  2. Highlight summarization in golf videos using audio signals

    Science.gov (United States)

    Kim, Hyoung-Gook; Kim, Jin Young

    2008-01-01

    In this paper, we present an automatic summarization of highlights in golf videos based on audio information alone without video information. The proposed highlight summarization system is carried out based on semantic audio segmentation and detection on action units from audio signals. Studio speech, field speech, music, and applause are segmented by means of sound classification. Swing is detected by the methods of impulse onset detection. Sounds like swing and applause form a complete action unit, while studio speech and music parts are used to anchor the program structure. With the advantage of highly precise detection of applause, highlights are extracted effectively. Our experimental results obtain high classification precision on 18 golf games. It proves that the proposed system is very effective and computationally efficient to apply the technology to embedded consumer electronic devices.

  3. Technical Evaluation Report 31: Internet Audio Products (3/ 3

    Directory of Open Access Journals (Sweden)

    Jim Rudolph

    2004-08-01

    Full Text Available Two contrasting additions to the online audio market are reviewed: iVocalize, a browser-based audio-conferencing software, and Skype, a PC-to-PC Internet telephone tool. These products are selected for review on the basis of their success in gaining rapid popular attention and usage during 2003-04. The iVocalize review emphasizes the product’s role in the development of a series of successful online audio communities – notably several serving visually impaired users. The Skype review stresses the ease with which the product may be used for simultaneous PC-to-PC communication among up to five users. Editor’s Note: This paper serves as an introduction to reports about online community building, and reviews of online products for disabled persons, in the next ten reports in this series. JPB, Series Ed.

  4. Audio frequency modulated RF discharge at atmospheric pressure

    Science.gov (United States)

    Braithwaite, Nicholas; Sutton, Yvonne; Sharp, David; Moore, Jon

    2008-10-01

    An atmospheric pressure RF arc discharge, generated using a low voltage chopper and a Tesla coil resonant at about 300 kHz, forms a stable, silent, flame-like luminous region some 3 mm in diameter and 40 mm long, rooted to the electrodes by visible hot spots. It is known and we have confirmed that audio frequency modulation of the drive voltage makes the discharge act as an audio loudspeaker (tweeter) with its monopole radiation pattern constrained only by the electrodes. Time resolved `total' optical emission reveals an intensity variation that is synchronous with the audio frequency. Electrical characterisation of the high frequency discharge has been carried out. In the steady state, the high frequency arc burns without generating significant quantities of ozone, as determined by a commercial ozone detector. This is consistent with the high gas temperature within the arc, as measured by optical emission spectroscopy of molecular nitrogen. Phase-locked emission measurements illustrate the acoustic coupling.

  5. Objective quality measurement for audio time-scale modification

    Science.gov (United States)

    Liu, Fang; Lee, Jae-Joon; Kuo, C. C. J.

    2003-11-01

    The recent ITU-T Recommendation P.862, known as the Perceptual Evaluation of Speech Quality (PESQ) is an objective end-to-end speech quality assessment method for telephone networks and speech codecs through the measurement of received audio quality. To ensure that certain network distortions will not affect the estimated subjective measurement determined by PESQ, the algorithm takes into account packet loss, short-term and long-term time warping resulted from delay variation. However, PESQ does not work well for time-scale audio modification or temporal clipping. We investigated the factors that impact the perceived quality when time-scale modification is involved. An objective measurement of time-scale modification is proposed in this research, where the cross-correlation values obtained from time-scale modification synchronization are used to evaluate the quality of a time-scaled audio sequence. This proposed objective measure has been verified by a subjective test.

  6. One Message, Many Voices: Mobile Audio Counselling in Health Education.

    Science.gov (United States)

    Pimmer, Christoph; Mbvundula, Francis

    2018-01-01

    Health workers' use of counselling information on their mobile phones for health education is a central but little understood phenomenon in numerous mobile health (mHealth) projects in Sub-Saharan Africa. Drawing on empirical data from an interpretive case study in the setting of the Millennium Villages Project in rural Malawi, this research investigates the ways in which community health workers (CHWs) perceive that audio-counselling messages support their health education practice. Three main themes emerged from the analysis: phone-aided audio counselling (1) legitimises the CHWs' use of mobile phones during household visits; (2) helps CHWs to deliver a comprehensive counselling message; (3) supports CHWs in persuading communities to change their health practices. The findings show the complexity and interplay of the multi-faceted, sociocultural, political, and socioemotional meanings associated with audio-counselling use. Practical implications and the demand for further research are discussed.

  7. Sistema de adquisición y procesamiento de audio

    OpenAIRE

    Pérez Segurado, Rubén

    2015-01-01

    El objetivo de este proyecto es el diseño y la implementación de una plataforma para un sistema de procesamiento de audio. El sistema recibirá una señal de audio analógica desde una fuente de audio, permitirá realizar un tratamiento digital de dicha señal y generará una señal procesada que se enviará a unos altavoces externos. Para la realización del sistema de procesamiento se empleará: - Un dispositivo FPGA de Lattice, modelo MachX02-7000-HE, en la cual estarán todas la...

  8. Music Identification System Using MPEG-7 Audio Signature Descriptors

    Science.gov (United States)

    You, Shingchern D.; Chen, Wei-Hwa; Chen, Woei-Kae

    2013-01-01

    This paper describes a multiresolution system based on MPEG-7 audio signature descriptors for music identification. Such an identification system may be used to detect illegally copied music circulated over the Internet. In the proposed system, low-resolution descriptors are used to search likely candidates, and then full-resolution descriptors are used to identify the unknown (query) audio. With this arrangement, the proposed system achieves both high speed and high accuracy. To deal with the problem that a piece of query audio may not be inside the system's database, we suggest two different methods to find the decision threshold. Simulation results show that the proposed method II can achieve an accuracy of 99.4% for query inputs both inside and outside the database. Overall, it is highly possible to use the proposed system for copyright control. PMID:23533359

  9. Music Identification System Using MPEG-7 Audio Signature Descriptors

    Directory of Open Access Journals (Sweden)

    Shingchern D. You

    2013-01-01

    Full Text Available This paper describes a multiresolution system based on MPEG-7 audio signature descriptors for music identification. Such an identification system may be used to detect illegally copied music circulated over the Internet. In the proposed system, low-resolution descriptors are used to search likely candidates, and then full-resolution descriptors are used to identify the unknown (query audio. With this arrangement, the proposed system achieves both high speed and high accuracy. To deal with the problem that a piece of query audio may not be inside the system’s database, we suggest two different methods to find the decision threshold. Simulation results show that the proposed method II can achieve an accuracy of 99.4% for query inputs both inside and outside the database. Overall, it is highly possible to use the proposed system for copyright control.

  10. Virtual environment display for a 3D audio room simulation

    Science.gov (United States)

    Chapin, William L.; Foster, Scott H.

    1992-01-01

    The development of a virtual environment simulation system integrating a 3D acoustic audio model with an immersive 3D visual scene is discussed. The system complements the acoustic model and is specified to: allow the listener to freely move about the space, a room of manipulable size, shape, and audio character, while interactively relocating the sound sources; reinforce the listener's feeling of telepresence in the acoustical environment with visual and proprioceptive sensations; enhance the audio with the graphic and interactive components, rather than overwhelm or reduce it; and serve as a research testbed and technology transfer demonstration. The hardware/software design of two demonstration systems, one installed and one portable, are discussed through the development of four iterative configurations.

  11. Audio engineering 101 a beginner's guide to music production

    CERN Document Server

    Dittmar, Tim

    2013-01-01

    Audio Engineering 101 is a real world guide for starting out in the recording industry. If you have the dream, the ideas, the music and the creativity but don't know where to start, then this book is for you!Filled with practical advice on how to navigate the recording world, from an author with first-hand, real-life experience, Audio Engineering 101 will help you succeed in the exciting, but tough and confusing, music industry. Covering all you need to know about the recording process, from the characteristics of sound to a guide to microphones to analog versus digital

  12. Real-time Loudspeaker Distance Estimation with Stereo Audio

    DEFF Research Database (Denmark)

    Nielsen, Jesper Kjær; Gaubitch, Nikolay; Heusdens, Richard

    2015-01-01

    Knowledge on how a number of loudspeakers are positioned relative to a listening position can be used to enhance the listening experience. Usually, these loudspeaker positions are estimated using calibration signals, either audible or psycho-acoustically hidden inside the desired audio signal....... In this paper, we propose to use the desired audio signal instead. Specifically, we treat the case of estimating the distance between two loudspeakers playing back a stereo music or speech signal. In this connection, we develop a real-time maximum likelihood estimator and demonstrate that it has a variance...

  13. Cambridge English First 2 audio CDs : authentic examination papers

    CERN Document Server

    2016-01-01

    Four authentic Cambridge English Language Assessment examination papers for the Cambridge English: First (FCE) exam. These examination papers for the Cambridge English: First (FCE) exam provide the most authentic exam preparation available, allowing candidates to familiarise themselves with the content and format of the exam and to practise useful exam techniques. The Audio CDs contain the recorded material to allow thorough preparation for the Listening paper and are designed to be used with the Student's Book. A Student's Book with or without answers and a Student's Book with answers and downloadable Audio are available separately. These tests are also available as Cambridge English: First Tests 5-8 on Testbank.org.uk

  14. Design of a WAV audio player based on K20

    Directory of Open Access Journals (Sweden)

    Xu Yu

    2016-01-01

    Full Text Available The designed player uses the Freescale Company’s MK20DX128VLH7 as the core control ship, and its hardware platform is equipped with VS1003 audio decoder, OLED display interface, USB interface and SD card slot. The player uses the open source embedded real-time operating system μC/OS-II, Freescale USB Stack V4.1.1 and FATFS, and a graphical user interface is developed to improve the user experience based on CGUI. In general, the designed WAV audio player has a strong applicability and a good practical value.

  15. DOA Estimation of Audio Sources in Reverberant Environments

    DEFF Research Database (Denmark)

    Jensen, Jesper Rindom; Nielsen, Jesper Kjær; Heusdens, Richard

    2016-01-01

    Reverberation is well-known to have a detrimental impact on many localization methods for audio sources. We address this problem by imposing a model for the early reflections as well as a model for the audio source itself. Using these models, we propose two iterative localization methods that est...... bias. Our simulation results show that we can estimate the DOA of the desired signal more accurately with this procedure compared to state-of-theart estimator in both synthetic and real data experiments with reverberation....

  16. AKTIVITAS SEKUNDER AUDIO UNTUK MENJAGA KEWASPADAAN PENGEMUDI MOBIL INDONESIA

    Directory of Open Access Journals (Sweden)

    Iftikar Zahedi Sutalaksana

    2013-03-01

    Full Text Available Tingkat kecelakaan lalu lintas yang melibatkan mobil di Indonesia semakin mengkhawatirkan. Tingginya peran faktor manusia sebagai penyebab utama kejadian kecelakaan patut diperhatikan. Penurunan kewaspadaan saat mengemudi akibat kantuk atau kelelahan merupakan salah satu kondisi yang mendorong terjadinya kecelakaan. Tulisan ini memaparkan aplikasi audio response test sebagai aktivitas sekunder dalam mengemudikan mobil. Response test yang dimaksud merupakan seperangkat aplikasi pada dashboard mobil yang menuntut respon pengemudi setiap stimulus suara bekerja. Audio response test ini diusulkan sebagai pemantau tingkat kewaspadaan pengemudi selama berkendara. Kewaspadaan pengemudi merupakan kondisi selama berkendara yang terjaga, awas, dan mampu memproses semua stimulus dengan baik. Hasil studi ini menghasilkan suatu bentuk audio response test yang terintegrasi dengan sistem berkendara di dalam mobil. Sumber bunyi diperdengarkan dengan intensitas konstan antara 80-85 dB. Bunyi akan berhenti jika pengemudi memberikan respon atas stimulus suara tersebut. Response test ini dirancang untuk mampu memantau tingkat kewaspadaan pengemudi selama berkendara. Penerapannya diharapkan mampu membantu menekan tingkat kecelakaan lalu lintas di Indonesia. Kata kunci: mengemudi, aktivitas sekunder, audio, kewaspadaan, response test   Abstract   The level of traffic accidents involving cars in Indonesia increasingly alarming. The high role of the human factor as the main cause of accident noteworthy. Decreased alertness while driving due to sleepiness or fatigue is one of the conditions that led to the accident. This paper describes an audio application response test as a secondary activity of driving a car. Response test is a set of applications on the dashboard of a car that demands a response driver each stimulus voice work. Audio response was proposed as test monitors the driver's level of alertness while driving. Vigilance driver was driving conditions during

  17. Audio Watermarking Based on HAS and Neural Networks in DCT Domain

    Directory of Open Access Journals (Sweden)

    Hung-Hsu Tsai

    2003-03-01

    Full Text Available We propose a new intelligent audio watermarking method based on the characteristics of the HAS and the techniques of neural networks in the DCT domain. The method makes the watermark imperceptible by using the audio masking characteristics of the HAS. Moreover, the method exploits a neural network for memorizing the relationships between the original audio signals and the watermarked audio signals. Therefore, the method is capable of extracting watermarks without original audio signals. Finally, the experimental results are also included to illustrate that the method significantly possesses robustness to be immune against common attacks for the copyright protection of digital audio.

  18. High Performance Low Cost Digitally Controlled Power Conversion Technology

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes

    2008-01-01

    Digital control of switch-mode power supplies and converters has within the last decade evolved from being an academic subject to an emerging market in the power electronics industry. This development has been pushed mainly by the computer industry that is looking towards digital power management...... the execution time of the software algorithm that realises the digital control law will constitute a considerable delay in the control loop. Digital signal controllers are powerful devices capable of performing arithmetic functions much faster than a microcontroller can. Digital signal controllers are well...... and an analogue to digital converter with a short sampling time. A digital self-oscillating modulator is proposed in the present thesis. The modulator is a free-running modulator which operates without an external carrier signal. Customised digital control solutions offers the best performance for non-isolated DC...

  19. Class D audio amplifier with 4th order output filter and self-oscillating full-state hysteresis based feedback driving capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    A practical solution is presented for the design of a non-isolated high voltage DC/AC power converter. The converter is intended to be used as a class D audio amplifier for a Dielectric Electro Active Polymer (DEAP) transducer. A simple and effective hysteretic control scheme for the converter...

  20. A conceptual framework for audio-visual museum media

    DEFF Research Database (Denmark)

    Kirkedahl Lysholm Nielsen, Mikkel

    2017-01-01

    and museum studies, existing case studies, and real life observations, the suggested framework instead stress particular characteristics of contextual use of audio-visual media in history museums, such as authenticity, virtuality, interativity, social context and spatial attributes of the communication...

  1. Towards a universal representation for audio information retrieval and analysis

    DEFF Research Database (Denmark)

    Jensen, Bjørn Sand; Troelsgaard, Rasmus; Larsen, Jan

    2013-01-01

    A fundamental and general representation of audio and music which integrates multi-modal data sources is important for both application and basic research purposes. In this paper we address this challenge by proposing a multi-modal version of the Latent Dirichlet Allocation model which provides a...

  2. The Single- and Multichannel Audio Recordings Database (SMARD)

    DEFF Research Database (Denmark)

    Nielsen, Jesper Kjær; Jensen, Jesper Rindom; Jensen, Søren Holdt

    2014-01-01

    A new single- and multichannel audio recordings database (SMARD) is presented in this paper. The database contains recordings from a box-shaped listening room for various loudspeaker and array types. The recordings were made for 48 different configurations of three different loudspeakers and four...

  3. Streaming Audio and Video: New Challenges and Opportunities for Museums.

    Science.gov (United States)

    Spadaccini, Jim

    Streaming audio and video present new challenges and opportunities for museums. Streaming media is easier to author and deliver to Internet audiences than ever before; digital video editing is commonplace now that the tools--computers, digital video cameras, and hard drives--are so affordable; the cost of serving video files across the Internet…

  4. Subband coding of digital audio signals without loss of quality

    NARCIS (Netherlands)

    Veldhuis, Raymond N.J.; Breeuwer, Marcel; van de Waal, Robbert

    1989-01-01

    A subband coding system for high quality digital audio signals is described. To achieve low bit rates at a high quality level, it exploits the simultaneous masking effect of the human ear. It is shown how this effect can be used in an adaptive bit-allocation scheme. The proposed approach has been

  5. Integrated Spacesuit Audio System Enhances Speech Quality and Reduces Noise

    Science.gov (United States)

    Huang, Yiteng Arden; Chen, Jingdong; Chen, Shaoyan Sharyl

    2009-01-01

    A new approach has been proposed for increasing astronaut comfort and speech capture. Currently, the special design of a spacesuit forms an extreme acoustic environment making it difficult to capture clear speech without compromising comfort. The proposed Integrated Spacesuit Audio (ISA) system is to incorporate the microphones into the helmet and use software to extract voice signals from background noise.

  6. Audio-Visual Perception System for a Humanoid Robotic Head

    Science.gov (United States)

    Viciana-Abad, Raquel; Marfil, Rebeca; Perez-Lorenzo, Jose M.; Bandera, Juan P.; Romero-Garces, Adrian; Reche-Lopez, Pedro

    2014-01-01

    One of the main issues within the field of social robotics is to endow robots with the ability to direct attention to people with whom they are interacting. Different approaches follow bio-inspired mechanisms, merging audio and visual cues to localize a person using multiple sensors. However, most of these fusion mechanisms have been used in fixed systems, such as those used in video-conference rooms, and thus, they may incur difficulties when constrained to the sensors with which a robot can be equipped. Besides, within the scope of interactive autonomous robots, there is a lack in terms of evaluating the benefits of audio-visual attention mechanisms, compared to only audio or visual approaches, in real scenarios. Most of the tests conducted have been within controlled environments, at short distances and/or with off-line performance measurements. With the goal of demonstrating the benefit of fusing sensory information with a Bayes inference for interactive robotics, this paper presents a system for localizing a person by processing visual and audio data. Moreover, the performance of this system is evaluated and compared via considering the technical limitations of unimodal systems. The experiments show the promise of the proposed approach for the proactive detection and tracking of speakers in a human-robot interactive framework. PMID:24878593

  7. Utilization of non-linear converters for audio amplification

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Birch, Thomas; Knott, Arnold

    2012-01-01

    . The introduction of non-linear converters for audio amplification defeats this limitation. A Cuk converter, designed to deliver an AC peak output voltage twice the supply voltage, is presented in this paper. A 3V prototype has been developed to prove the concept. The prototype shows that it is possible to achieve...

  8. Audio Quality Assurance : An Application of Cross Correlation

    DEFF Research Database (Denmark)

    Jurik, Bolette Ammitzbøll; Nielsen, Jesper Asbjørn Sindahl

    2012-01-01

    We describe algorithms for automated quality assurance on content of audio files in context of preservation actions and access. The algorithms use cross correlation to compare the sound waves. They are used to do overlap analysis in an access scenario, where preserved radio broadcasts are used...

  9. The relationship between basic audio quality and overall listening experience.

    Science.gov (United States)

    Schoeffler, Michael; Herre, Jürgen

    2016-09-01

    Basic audio quality (BAQ) is a well-known perceptual attribute, which is rated in various listening test methods to measure the performance of audio systems. Unfortunately, when it comes to purchasing audio systems, BAQ might not have a significant influence on the customers' buying decisions since other factors, like brand loyalty, might be more important. In contrast to BAQ, overall listening experience (OLE) is an affective attribute which incorporates all aspects that are important to an individual assessor, including his or her preference for music genre and audio quality. In this work, the relationship between BAQ and OLE is investigated in more detail. To this end, an experiment was carried out, in which participants rated the BAQ and the OLE of music excerpts with different timbral and spatial degradations. In a between-group-design procedure, participants were assigned into two groups, in each of which a different set of stimuli was rated. The results indicate that rating of both attributes, BAQ and OLE, leads to similar rankings, even if a different set of stimuli is rated. In contrast to the BAQ ratings, which were more influenced by timbral than spatial degradations, the OLE ratings were almost equally influenced by timbral and spatial degradations.

  10. Dynamically-Loaded Hardware Libraries (HLL) Technology for Audio Applications

    DEFF Research Database (Denmark)

    Esposito, A.; Lomuscio, A.; Nunzio, L. Di

    2016-01-01

    In this work, we apply hardware acceleration to embedded systems running audio applications. We present a new framework, Dynamically-Loaded Hardware Libraries or HLL, to dynamically load hardware libraries on reconfigurable platforms (FPGAs). Provided a library of application-specific processors,...

  11. Turkish Music Genre Classification using Audio and Lyrics Features

    Directory of Open Access Journals (Sweden)

    Önder ÇOBAN

    2017-05-01

    Full Text Available Music Information Retrieval (MIR has become a popular research area in recent years. In this context, researchers have developed music information systems to find solutions for such major problems as automatic playlist creation, hit song detection, and music genre or mood classification. Meta-data information, lyrics, or melodic content of music are used as feature resource in previous works. However, lyrics do not often used in MIR systems and the number of works in this field is not enough especially for Turkish. In this paper, firstly, we have extended our previously created Turkish MIR (TMIR dataset, which comprises of Turkish lyrics, by including the audio file of each song. Secondly, we have investigated the effect of using audio and textual features together or separately on automatic Music Genre Classification (MGC. We have extracted textual features from lyrics using different feature extraction models such as word2vec and traditional Bag of Words. We have conducted our experiments on Support Vector Machine (SVM algorithm and analysed the impact of feature selection and different feature groups on MGC. We have considered lyrics based MGC as a text classification task and also investigated the effect of term weighting method. Experimental results show that textual features can also be effective as well as audio features for Turkish MGC, especially when a supervised term weighting method is employed. We have achieved the highest success rate as 99,12\\% by using both audio and textual features together.

  12. A listening test system for automotive audio - listeners

    DEFF Research Database (Denmark)

    Choisel, Sylvain; Hegarty, Patrick; Christensen, Flemming

    2007-01-01

    A series of experiments was conducted in order to validate an experimental procedure to perform listening tests on car audio systems in a simulation of the car environment in a laboratory, using binaural synthesis with head-tracking. Seven experts and 40 non-expert listeners rated a range of stim...

  13. Audio-Visual Aid in Teaching "Fatty Liver"

    Science.gov (United States)

    Dash, Sambit; Kamath, Ullas; Rao, Guruprasad; Prakash, Jay; Mishra, Snigdha

    2016-01-01

    Use of audio visual tools to aid in medical education is ever on a rise. Our study intends to find the efficacy of a video prepared on "fatty liver," a topic that is often a challenge for pre-clinical teachers, in enhancing cognitive processing and ultimately learning. We prepared a video presentation of 11:36 min, incorporating various…

  14. Audio-haptic interaction in simulated walking experiences

    DEFF Research Database (Denmark)

    Serafin, Stefania

    2011-01-01

    In this paper an overview of the work conducted on audio-haptic physically based simulation and evaluation of walking is provided. This work has been performed in the context of the Natural Interactive Walking (NIW) project, whose goal is to investigate possibilities for the integrated and interc...

  15. Audio-visual materials usage preference among agricultural ...

    African Journals Online (AJOL)

    It was found that respondents preferred radio, television, poster, advert, photographs, specimen, bulletin, magazine, cinema, videotape, chalkboard, and bulletin board as audio-visual materials for extension work. These are the materials that can easily be manipulated and utilized for extension work. Nigerian Journal of ...

  16. Adding Audio Description: Does It Make a Difference?

    Science.gov (United States)

    Schmeidler, Emilie; Kirchner, Corinne

    2001-01-01

    A study involving 111 adults with blindness examined the impact of watching television science programs with and without audio description. Results indicate respondents gained and retained more information from watching programs with description. They reported that the description makes the program more enjoyable, interesting, and informative.…

  17. Auteur Description: From the Director's Creative Vision to Audio Description

    Science.gov (United States)

    Szarkowska, Agnieszka

    2013-01-01

    In this report, the author follows the suggestion that a film director's creative vision should be incorporated into Audio description (AD), a major technique for making films, theater performances, operas, and other events accessible to people who are blind or have low vision. The author presents a new type of AD for auteur and artistic films:…

  18. Estimation of macro sleep stages from whole night audio analysis.

    Science.gov (United States)

    Dafna, E; Halevi, M; Ben Or, D; Tarasiuk, A; Zigel, Y

    2016-08-01

    During routine sleep diagnostic procedure, sleep is broadly divided into three states: rapid eye movement (REM), non-REM (NREM) states, and wake, frequently named macro-sleep stages (MSS). In this study, we present a pioneering attempt for MSS detection using full night audio analysis. Our working hypothesis is that there might be differences in sound properties within each MSS due to breathing efforts (or snores) and body movements in bed. In this study, audio signals of 35 patients referred to a sleep laboratory were recorded and analyzed. An additional 178 subjects were used to train a probabilistic time-series model for MSS staging across the night. The audio-based system was validated on 20 out of the 35 subjects. System accuracy for estimating (detecting) epoch-by-epoch wake/REM/NREM states for a given subject is 74% (69% for wake, 54% for REM, and 79% NREM). Mean error (absolute difference) was 36±34 min for detecting total sleep time, 17±21 min for sleep latency, 5±5% for sleep efficiency, and 7±5% for REM percentage. These encouraging results indicate that audio-based analysis can provide a simple and comfortable alternative method for ambulatory evaluation of sleep and its disorders.

  19. Phase Synchronization in Human EEG During Audio-Visual Stimulation

    Czech Academy of Sciences Publication Activity Database

    Teplan, M.; Šušmáková, K.; Paluš, Milan; Vejmelka, Martin

    2009-01-01

    Roč. 28, - (2009), s. 80-84 ISSN 1536-8378 Grant - others:Bilateral project between Slovak AS and AS CR(CZ-SK) Modern methods for evaluation of electrophysiological signals Source of funding: V - iné verejné zdroje Keywords : synchronization * EEG * wavelet * audio- visual stimulation Subject RIV: FH - Neurology Impact factor: 0.729, year: 2009

  20. Real-Time Audio-Visual Analysis for Multiperson Videoconferencing

    Directory of Open Access Journals (Sweden)

    Petr Motlicek

    2013-01-01

    Full Text Available We describe the design of a system consisting of several state-of-the-art real-time audio and video processing components enabling multimodal stream manipulation (e.g., automatic online editing for multiparty videoconferencing applications in open, unconstrained environments. The underlying algorithms are designed to allow multiple people to enter, interact, and leave the observable scene with no constraints. They comprise continuous localisation of audio objects and its application for spatial audio object coding, detection, and tracking of faces, estimation of head poses and visual focus of attention, detection and localisation of verbal and paralinguistic events, and the association and fusion of these different events. Combined all together, they represent multimodal streams with audio objects and semantic video objects and provide semantic information for stream manipulation systems (like a virtual director. Various experiments have been performed to evaluate the performance of the system. The obtained results demonstrate the effectiveness of the proposed design, the various algorithms, and the benefit of fusing different modalities in this scenario.

  1. The Role of Audio Media in the Lives of Children.

    Science.gov (United States)

    Christenson, Peter G.; Lindlof, Thomas R.

    Mass communication researchers have largely ignored the role of audio media and popular music in the lives of children, yet the available evidence shows that children do listen. Extant studies yield a consistent developmental portrait of childrens' listening frequency, but there is a notable lack of programatic research over the past decade, one…

  2. Advanced Audio Interface for Phonetic Speech Recognition in a High Noise Environment

    National Research Council Canada - National Science Library

    2000-01-01

    Standard Object Systems, Inc. (SOS) has used its existing technology in phonetic speech recognition, audio signal processing, and multilingual language translation to design and demonstrate an advanced audio interface for speech...

  3. MedlinePlus FAQ: Is audio description available for videos on MedlinePlus?

    Science.gov (United States)

    ... https://medlineplus.gov/faq/audiodescription.html Question: Is audio description available for videos on MedlinePlus? To use ... features on this page, please enable JavaScript. Answer: Audio description of videos helps make the content of ...

  4. Overview of the 2015 Workshop on Speech, Language and Audio in Multimedia

    NARCIS (Netherlands)

    Gravier, Guillaume; Jones, Gareth J.F.; Larson, Martha; Ordelman, Roeland J.F.

    2015-01-01

    The Workshop on Speech, Language and Audio in Multimedia (SLAM) positions itself at at the crossroad of multiple scientific fields - music and audio processing, speech processing, natural language processing and multimedia - to discuss and stimulate research results, projects, datasets and

  5. Audio-Visual Speaker Diarization Based on Spatiotemporal Bayesian Fusion.

    Science.gov (United States)

    Gebru, Israel D; Ba, Sileye; Li, Xiaofei; Horaud, Radu

    2018-05-01

    Speaker diarization consists of assigning speech signals to people engaged in a dialogue. An audio-visual spatiotemporal diarization model is proposed. The model is well suited for challenging scenarios that consist of several participants engaged in multi-party interaction while they move around and turn their heads towards the other participants rather than facing the cameras and the microphones. Multiple-person visual tracking is combined with multiple speech-source localization in order to tackle the speech-to-person association problem. The latter is solved within a novel audio-visual fusion method on the following grounds: binaural spectral features are first extracted from a microphone pair, then a supervised audio-visual alignment technique maps these features onto an image, and finally a semi-supervised clustering method assigns binaural spectral features to visible persons. The main advantage of this method over previous work is that it processes in a principled way speech signals uttered simultaneously by multiple persons. The diarization itself is cast into a latent-variable temporal graphical model that infers speaker identities and speech turns, based on the output of an audio-visual association process, executed at each time slice, and on the dynamics of the diarization variable itself. The proposed formulation yields an efficient exact inference procedure. A novel dataset, that contains audio-visual training data as well as a number of scenarios involving several participants engaged in formal and informal dialogue, is introduced. The proposed method is thoroughly tested and benchmarked with respect to several state-of-the art diarization algorithms.

  6. Electronic Power Transformer for Power Distribution Networks

    Directory of Open Access Journals (Sweden)

    Ermuraсhi Iu.V.

    2017-12-01

    Full Text Available Reducing losses in electricity distribution networks is a current technical problem. This issue also has social and environmental aspects. As a promising solution one can examine the direct distribution from the medium voltage power network using new equipment based on the use of power electronics. The aim of the paper is to propose and argue an innovative technical solution for the realization of the Solid State Transformer (SST in order to decrease the number of energy transformation stages compared to the known solutions, simplifying the topology of the functional scheme with the reduction of production costs and the loss of energy in transformers used in electrical distribution networks. It is proposed the solution of simplifying the topology of the AC/AC electronic transformer by reducing the number of passive electronic components (resistors, inductors, capacitors and active (transistors. The inverter of the SST transformer ensures the switching mode of the transistors, using for this purpose the inductance of the magnetic leakage flux of the high frequency transformer. The robustness of the laboratory sample of the SST 10 / 0.22 kV transformer with the power of 20 kW was manufactured and tested. Testing of the laboratory sample confirmed the functionality of the proposed scheme and the possibility of switching of the transistors to at zero current (ZCS mode with the reduction of the energy losses. In the proposed converter a single high-frequency transformer with a simplified construction with two windings is used, which reduces its mass and the cost of making the transformer. The reduction in the manufacturing cost of the converter is also due to the decrease in the number of links between the functional elements.

  7. Documentary management of the sport audio-visual information in the generalist televisions

    OpenAIRE

    Jorge Caldera Serrano; Felipe Alonso

    2007-01-01

    The management of the sport audio-visual documentation of the Information Systems of the state, zonal and local chains is analyzed within the framework. For it it is made makes a route by the documentary chain that makes the sport audio-visual information with the purpose of being analyzing each one of the parameters, showing therefore a series of recommendations and norms for the preparation of the sport audio-visual registry. Evidently the audio-visual sport documentation difference i...

  8. Audio-visual onset differences are used to determine syllable identity for ambiguous audio-visual stimulus pairs

    NARCIS (Netherlands)

    Ten Oever, Sanne; Sack, Alexander T; Wheat, Katherine L; Bien, Nina; van Atteveldt, Nienke

    2013-01-01

    Content and temporal cues have been shown to interact during audio-visual (AV) speech identification. Typically, the most reliable unimodal cue is used more strongly to identify specific speech features; however, visual cues are only used if the AV stimuli are presented within a certain temporal

  9. Amping it up on a small budget: Transforming inexpensive, commercial audio and video components into a useful charged particle spectrometer

    Science.gov (United States)

    Pallone, Arthur

    Necessity often leads to inspiration. Such was the case when a traditional amplifier quit working during the collection of an alpha particle spectrum. I had a 15 battery-powered audio amplifier in my box of project electronics so I connected it between the preamplifier and the multichannel analyzer. The alpha particle spectrum that appeared on the computer screen matched expectations even without correcting for impedance mismatches. Encouraged by this outcome, I have begun to systematically replace each of the parts in a traditional charged particle spectrometer with audio and video components available through consumer electronics stores with the goal of producing an inexpensive charged particle spectrometer for use in education and research. Hopefully my successes, setbacks, and results to date described in this presentation will inform and inspire others.

  10. 47 CFR 73.9005 - Compliance requirements for covered demodulator products: Audio.

    Science.gov (United States)

    2010-10-01

    ... products: Audio. 73.9005 Section 73.9005 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED....9005 Compliance requirements for covered demodulator products: Audio. Except as otherwise provided in §§ 73.9003(a) or 73.9004(a), covered demodulator products shall not output the audio portions of...

  11. 76 FR 591 - Determination of Rates and Terms for Preexisting Subscription and Satellite Digital Audio Radio...

    Science.gov (United States)

    2011-01-05

    ... of Rates and Terms for Preexisting Subscription and Satellite Digital Audio Radio Services AGENCY... satellite digital audio radio services for the digital performance of sound recordings and the making of... both preexisting subscription services (``PSS'') and satellite digital audio radio services...

  12. Effects of Hearing Protection Device Attenuation on Unmanned Aerial Vehicle (UAV) Audio Signatures

    Science.gov (United States)

    2016-03-01

    UAV) Audio Signatures by Melissa Bezandry, Adrienne Raglin, and John Noble Approved for public release; distribution...Research Laboratory Effects of Hearing Protection Device Attenuation on Unmanned Aerial Vehicle (UAV) Audio Signatures by Melissa Bezandry...Aerial Vehicle (UAV) Audio Signatures 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Melissa Bezandry

  13. Responding Effectively to Composition Students: Comparing Student Perceptions of Written and Audio Feedback

    Science.gov (United States)

    Bilbro, J.; Iluzada, C.; Clark, D. E.

    2013-01-01

    The authors compared student perceptions of audio and written feedback in order to assess what types of students may benefit from receiving audio feedback on their essays rather than written feedback. Many instructors previously have reported the advantages they see in audio feedback, but little quantitative research has been done on how the…

  14. 16 CFR 307.8 - Requirements for disclosure in audiovisual and audio advertising.

    Science.gov (United States)

    2010-01-01

    ... and audio advertising. 307.8 Section 307.8 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS... ACT OF 1986 Advertising Disclosures § 307.8 Requirements for disclosure in audiovisual and audio... and in graphics so that it is easily legible. If the advertisement has an audio component, the warning...

  15. Interactive 3D audio: Enhancing awareness of details in immersive soundscapes?

    DEFF Research Database (Denmark)

    Schmidt, Mikkel Nørgaard; Schwartz, Stephen; Larsen, Jan

    2012-01-01

    Spatial audio and the possibility of interacting with the audio environment is thought to increase listeners' attention to details in a soundscape. This work examines if interactive 3D audio enhances listeners' ability to recall details in a soundscape. Nine different soundscapes were constructed...

  16. Parametric Packet-Layer Model for Evaluation Audio Quality in Multimedia Streaming Services

    Science.gov (United States)

    Egi, Noritsugu; Hayashi, Takanori; Takahashi, Akira

    We propose a parametric packet-layer model for monitoring audio quality in multimedia streaming services such as Internet protocol television (IPTV). This model estimates audio quality of experience (QoE) on the basis of quality degradation due to coding and packet loss of an audio sequence. The input parameters of this model are audio bit rate, sampling rate, frame length, packet-loss frequency, and average burst length. Audio bit rate, packet-loss frequency, and average burst length are calculated from header information in received IP packets. For sampling rate, frame length, and audio codec type, the values or the names used in monitored services are input into this model directly. We performed a subjective listening test to examine the relationships between these input parameters and perceived audio quality. The codec used in this test was the Advanced Audio Codec-Low Complexity (AAC-LC), which is one of the international standards for audio coding. On the basis of the test results, we developed an audio quality evaluation model. The verification results indicate that audio quality estimated by the proposed model has a high correlation with perceived audio quality.

  17. Low-delay predictive audio coding for the HIVITS HDTV codec

    Science.gov (United States)

    McParland, A. K.; Gilchrist, N. H. C.

    1995-01-01

    The status of work relating to predictive audio coding, as part of the European project on High Quality Video Telephone and HD(TV) Systems (HIVITS), is reported. The predictive coding algorithm is developed, along with six-channel audio coding and decoding hardware. Demonstrations of the audio codec operating in conjunction with the video codec, are given.

  18. High-Performance Control in Radio Frequency Power Amplification Systems

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Kofod

    frequency power amplifiers (RFPAs) in conjunction with cartesian feedback (CFB) used to linearize the overall transmitter system. On a system level, it is demonstrated how envelope tracking is particularly useful for RF carriers with high peak-to-average power ratios, such as TEDS with 10dB. It is also......This thesis presents a broad study of methods for increasing the efficiency of narrow-band radio transmitters. The study is centered around the base station application and TETRA/TEDS networks. The general solution space studied is that of envelope tracking applied to linear class-A/B radio....... It is clearly shown that single-phase switch-mode control systems based on oscillation (controlled unstable operation) of the whole power train provide the highest possible control bandwidth. A study of the limitations of cartesian feedback is also included. It is shown that bandwidths in excess of 4MHz can...

  19. Survey of error concealment schemes for real-time audio transmission systems

    OpenAIRE

    Robles Moya, Aránzazu

    2012-01-01

    This thesis presents an overview of the main strategies employed for error detection and error concealment in different real-time transmission systems for digital audio. The “Adaptive Differential Pulse-Code Modulation (ADPCM)”, the “Audio Processing Technology Apt-x100”, the “Extended Adaptive Multi-Rate Wideband (AMR-WB+)”, the “Advanced Audio Coding (AAC)”, the “MPEG-1 Audio Layer II (MP2)”, the “MPEG-1 Audio Layer III (MP3)” and finally the “Adaptive Transform Coder 3 (AC3)” are considere...

  20. An introduction to audio content analysis applications in signal processing and music informatics

    CERN Document Server

    Lerch, Alexander

    2012-01-01

    "With the proliferation of digital audio distribution over digital media, audio content analysis is fast becoming a requirement for designers of intelligent signal-adaptive audio processing systems. Written by a well-known expert in the field, this book provides quick access to different analysis algorithms and allows comparison between different approaches to the same task, making it useful for newcomers to audio signal processing and industry experts alike. A review of relevant fundamentals in audio signal processing, psychoacoustics, and music theory, as well as downloadable MATLAB files are also included"--

  1. “Wrapping” X3DOM around Web Audio API

    Directory of Open Access Journals (Sweden)

    Andreas Stamoulias

    2015-12-01

    Full Text Available Spatial sound has a conceptual role in the Web3D environments, due to highly realism scenes that can provide. Lately the efforts are concentrated on the extension of the X3D/ X3DOM through spatial sound attributes. This paper presents a novel method for the introduction of spatial sound components in the X3DOM framework, based on X3D specification and Web Audio API. The proposed method incorporates the introduction of enhanced sound nodes for X3DOM which are derived by the implementation of the X3D standard components, enriched with accessional features of Web Audio API. Moreover, several examples-scenarios developed for the evaluation of our approach. The implemented examples established the achievability of new registered nodes in X3DOM, for spatial sound characteristics in Web3D virtual worlds.

  2. Audio teleconferencing: creative use of a forgotten innovation.

    Science.gov (United States)

    Mather, Carey; Marlow, Annette

    2012-06-01

    As part of a regional School of Nursing and Midwifery's commitment to addressing recruitment and retention issues, approximately 90% of second year undergraduate student nurses undertake clinical placements at: multipurpose centres; regional or district hospitals; aged care; or community centres based in rural and remote regions within the State. The remaining 10% undertake professional experience placement in urban areas only. This placement of a large cohort of students, in low numbers in a variety of clinical settings, initiated the need to provide consistent support to both students and staff at these facilities. Subsequently the development of an audio teleconferencing model of clinical facilitation to guide student teaching and learning and to provide support to registered nurse preceptors in clinical practice was developed. This paper draws on Weimer's 'Personal Accounts of Change' approach to describe, discuss and evaluate the modifications that have occurred since the inception of this audio teleconferencing model (Weimer, 2006).

  3. Digital audio recordings improve the outcomes of patient consultations

    DEFF Research Database (Denmark)

    Wolderslund, Maiken; Kofoed, Poul-Erik; Holst, René

    2017-01-01

    OBJECTIVES: To investigate the effects on patients' outcome of the consultations when provided with: a Digital Audio Recording (DAR) of the consultation and a Question Prompt List (QPL). METHODS: This is a three-armed randomised controlled cluster trial. One group of patients received standard care......, while the other two groups received either the QPL in combination with a recording of their consultation or only the recording. Patients from four outpatient clinics participated: Paediatric, Orthopaedic, Internal Medicine, and Urology. The effects were evaluated by patient-administered questionnaires...... of their consultation positively influences the patients' perception of having adequate information after the consultation. PRACTICE IMPLICATIONS: The implementation of a QPL and audio recording of consultations should be considered in routine practice....

  4. Exploiting Acoustic Similarity of Propagating Paths for Audio Signal Separation

    Directory of Open Access Journals (Sweden)

    Yin Bin

    2003-01-01

    Full Text Available Blind signal separation can easily find its position in audio applications where mutually independent sources need to be separated from their microphone mixtures while both room acoustics and sources are unknown. However, the conventional separation algorithms can hardly be implemented in real time due to the high computational complexity. The computational load is mainly caused by either direct or indirect estimation of thousands of acoustic parameters. Aiming at the complexity reduction, in this paper, the acoustic paths are investigated through an acoustic similarity index (ASI. Then a new mixing model is proposed. With closely spaced microphones (5–10 cm apart, the model relieves the computational load of the separation algorithm by reducing the number and length of the filters to be adjusted. To cope with real situations, a blind audio signal separation algorithm (BLASS is developed on the proposed model. BLASS only uses the second-order statistics (SOS and performs efficiently in frequency domain.

  5. A Robust Zero-Watermarking Algorithm for Audio

    Directory of Open Access Journals (Sweden)

    Jie Zhu

    2008-03-01

    Full Text Available In traditional watermarking algorithms, the insertion of watermark into the host signal inevitably introduces some perceptible quality degradation. Another problem is the inherent conflict between imperceptibility and robustness. Zero-watermarking technique can solve these problems successfully. Instead of embedding watermark, the zero-watermarking technique extracts some essential characteristics from the host signal and uses them for watermark detection. However, most of the available zero-watermarking schemes are designed for still image and their robustness is not satisfactory. In this paper, an efficient and robust zero-watermarking technique for audio signal is presented. The multiresolution characteristic of discrete wavelet transform (DWT, the energy compression characteristic of discrete cosine transform (DCT, and the Gaussian noise suppression property of higher-order cumulant are combined to extract essential features from the host audio signal and they are then used for watermark recovery. Simulation results demonstrate the effectiveness of our scheme in terms of inaudibility, detection reliability, and robustness.

  6. Underdetermined Blind Audio Source Separation Using Modal Decomposition

    Directory of Open Access Journals (Sweden)

    Abdeldjalil Aïssa-El-Bey

    2007-03-01

    Full Text Available This paper introduces new algorithms for the blind separation of audio sources using modal decomposition. Indeed, audio signals and, in particular, musical signals can be well approximated by a sum of damped sinusoidal (modal components. Based on this representation, we propose a two-step approach consisting of a signal analysis (extraction of the modal components followed by a signal synthesis (grouping of the components belonging to the same source using vector clustering. For the signal analysis, two existing algorithms are considered and compared: namely the EMD (empirical mode decomposition algorithm and a parametric estimation algorithm using ESPRIT technique. A major advantage of the proposed method resides in its validity for both instantaneous and convolutive mixtures and its ability to separate more sources than sensors. Simulation results are given to compare and assess the performance of the proposed algorithms.

  7. Underdetermined Blind Audio Source Separation Using Modal Decomposition

    Directory of Open Access Journals (Sweden)

    Aïssa-El-Bey Abdeldjalil

    2007-01-01

    Full Text Available This paper introduces new algorithms for the blind separation of audio sources using modal decomposition. Indeed, audio signals and, in particular, musical signals can be well approximated by a sum of damped sinusoidal (modal components. Based on this representation, we propose a two-step approach consisting of a signal analysis (extraction of the modal components followed by a signal synthesis (grouping of the components belonging to the same source using vector clustering. For the signal analysis, two existing algorithms are considered and compared: namely the EMD (empirical mode decomposition algorithm and a parametric estimation algorithm using ESPRIT technique. A major advantage of the proposed method resides in its validity for both instantaneous and convolutive mixtures and its ability to separate more sources than sensors. Simulation results are given to compare and assess the performance of the proposed algorithms.

  8. Audio Visual Media Components in Educational Game for Elementary Students

    Directory of Open Access Journals (Sweden)

    Meilani Hartono

    2016-12-01

    Full Text Available The purpose of this research was to review and implement interactive audio visual media used in an educational game to improve elementary students’ interest in learning mathematics. The game was developed for desktop platform. The art of the game was set as 2D cartoon art with animation and audio in order to make students more interest. There were four mini games developed based on the researches on mathematics study. Development method used was Multimedia Development Life Cycle (MDLC that consists of requirement, design, development, testing, and implementation phase. Data collection methods used are questionnaire, literature study, and interview. The conclusion is elementary students interest with educational game that has fun and active (moving objects, with fast tempo of music, and carefree color like blue. This educational game is hoped to be an alternative teaching tool combined with conventional teaching method.

  9. Amplitude Modulated Sinusoidal Signal Decomposition for Audio Coding

    DEFF Research Database (Denmark)

    Christensen, M. G.; Jacobson, A.; Andersen, S. V.

    2006-01-01

    In this paper, we present a decomposition for sinusoidal coding of audio, based on an amplitude modulation of sinusoids via a linear combination of arbitrary basis vectors. The proposed method, which incorporates a perceptual distortion measure, is based on a relaxation of a nonlinear least......-squares minimization. Rate-distortion curves and listening tests show that, compared to a constant-amplitude sinusoidal coder, the proposed decomposition offers perceptually significant improvements in critical transient signals....

  10. Voice activity detection using audio-visual information

    DEFF Research Database (Denmark)

    Petsatodis, Theodore; Pnevmatikakis, Aristodemos; Boukis, Christos

    2009-01-01

    -decision scheme. The Mel-Frequency Cepstral Coefficients and the vertical mouth opening are the chosen audio and visual features respectively, both augmented with their first-order derivatives. The proposed system is assessed using far-field recordings from four different speakers and under various levels...... of additive white Gaussian noise, to obtain a performance superior than that which each unimodal component alone can achieve....

  11. Entropy coding of Quantized Spectral Components in FDLP audio codec

    OpenAIRE

    Motlicek, Petr; Ganapathy, Sriram; Hermansky, Hynek

    2008-01-01

    Audio codec based on Frequency Domain Linear Prediction (FDLP) exploits auto-regressive modeling to approximate instantaneous energy in critical frequency sub-bands of relatively long input segments. Current version of the FDLP codec operating at 66 kbps has shown to provide comparable subjective listening quality results to the state-of-the-art codecs on similar bit-rates even without employing strategic blocks, such as entropy coding or simultaneous masking. This paper describes an experime...

  12. Studies on a Spatialized Audio Interface for Sonar

    Science.gov (United States)

    2011-10-03

    addition of spatialized audio to visual displays for sonar is much akin to the development of talking movies in the early days of cinema and can be...exclusion of all others. This is a very different use of “space” when compared with the much broader and substantially older literature in spatial cognition...real-world scenarios after first showing that the algorithm, as published in the open literature , introduces substantial unwanted artifacts into

  13. Prototype of speech translation system for audio effective communication

    OpenAIRE

    Rojas Bello, Richard; Araya Araya, Erick; Vidal Vidal, Luis

    2006-01-01

    The present document exposes the development of a prototype of translation system as a Thesis Project. It consists basically on the capture of a flow of voice from the emitter, integrating advanced technologies of voice recognition, instantaneous translation and communication over the internet protocol RTP/RTCP (Real time Transport Protocol) to send information in real-time to the receiver. This prototype doesn't transmit image, it only boards the audio stage. Finally, the project besides emb...

  14. Modular Sensor Environment : Audio Visual Industry Monitoring Applications

    OpenAIRE

    Guillot, Calvin

    2017-01-01

    This work was made for Electro Waves Oy. The company specializes in Audio-visual services and interactive systems. The purpose of this work is to design and implement a modular sensor environment for the company, which will be used for developing automated systems. This thesis begins with an introduction to sensor systems and their different topologies. It is followed by an introduction to the technologies used in this project. The system is divided in three parts. The client, tha...

  15. Virtual environment display for a 3D audio room simulation

    Science.gov (United States)

    Chapin, William L.; Foster, Scott

    1992-06-01

    Recent developments in virtual 3D audio and synthetic aural environments have produced a complex acoustical room simulation. The acoustical simulation models a room with walls, ceiling, and floor of selected sound reflecting/absorbing characteristics and unlimited independent localizable sound sources. This non-visual acoustic simulation, implemented with 4 audio ConvolvotronsTM by Crystal River Engineering and coupled to the listener with a Poihemus IsotrakTM, tracking the listener's head position and orientation, and stereo headphones returning binaural sound, is quite compelling to most listeners with eyes closed. This immersive effect should be reinforced when properly integrated into a full, multi-sensory virtual environment presentation. This paper discusses the design of an interactive, visual virtual environment, complementing the acoustic model and specified to: 1) allow the listener to freely move about the space, a room of manipulable size, shape, and audio character, while interactively relocating the sound sources; 2) reinforce the listener's feeling of telepresence into the acoustical environment with visual and proprioceptive sensations; 3) enhance the audio with the graphic and interactive components, rather than overwhelm or reduce it; and 4) serve as a research testbed and technology transfer demonstration. The hardware/software design of two demonstration systems, one installed and one portable, are discussed through the development of four iterative configurations. The installed system implements a head-coupled, wide-angle, stereo-optic tracker/viewer and multi-computer simulation control. The portable demonstration system implements a head-mounted wide-angle, stereo-optic display, separate head and pointer electro-magnetic position trackers, a heterogeneous parallel graphics processing system, and object oriented C++ program code.

  16. Sounding better: fast audio cues increase walk speed in treadmill-mediated virtual rehabilitation environments.

    Science.gov (United States)

    Powell, Wendy; Stevens, Brett; Hand, Steve; Simmonds, Maureen

    2010-01-01

    Music or sound effects are often used to enhance Virtual Environments, but it is not known how this audio may influence gait speed. This study investigated the influence of audio cue tempo on treadmill walking with and without visual flow. The walking speeds of 11 individuals were recorded during exposure to a range of audio cue rates. There was a significant effect of audio tempo without visual flow, with a 16% increase in walk speed with faster audio cue tempos. Audio with visual flow resulted in a smaller but still significant increase in walking speed (8%). The results suggest that the inclusion of faster rate audio cues may be of benefit in improving walk speed in virtual rehabilitation.

  17. The method of narrow-band audio classification based on universal noise background model

    Science.gov (United States)

    Rui, Rui; Bao, Chang-chun

    2013-03-01

    Audio classification is the basis of content-based audio analysis and retrieval. The conventional classification methods mainly depend on feature extraction of audio clip, which certainly increase the time requirement for classification. An approach for classifying the narrow-band audio stream based on feature extraction of audio frame-level is presented in this paper. The audio signals are divided into speech, instrumental music, song with accompaniment and noise using the Gaussian mixture model (GMM). In order to satisfy the demand of actual environment changing, a universal noise background model (UNBM) for white noise, street noise, factory noise and car interior noise is built. In addition, three feature schemes are considered to optimize feature selection. The experimental results show that the proposed algorithm achieves a high accuracy for audio classification, especially under each noise background we used and keep the classification time less than one second.

  18. Comparison of Linear Prediction Models for Audio Signals

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available While linear prediction (LP has become immensely popular in speech modeling, it does not seem to provide a good approach for modeling audio signals. This is somewhat surprising, since a tonal signal consisting of a number of sinusoids can be perfectly predicted based on an (all-pole LP model with a model order that is twice the number of sinusoids. We provide an explanation why this result cannot simply be extrapolated to LP of audio signals. If noise is taken into account in the tonal signal model, a low-order all-pole model appears to be only appropriate when the tonal components are uniformly distributed in the Nyquist interval. Based on this observation, different alternatives to the conventional LP model can be suggested. Either the model should be changed to a pole-zero, a high-order all-pole, or a pitch prediction model, or the conventional LP model should be preceded by an appropriate frequency transform, such as a frequency warping or downsampling. By comparing these alternative LP models to the conventional LP model in terms of frequency estimation accuracy, residual spectral flatness, and perceptual frequency resolution, we obtain several new and promising approaches to LP-based audio modeling.

  19. Automatic summarization of soccer highlights using audio-visual descriptors.

    Science.gov (United States)

    Raventós, A; Quijada, R; Torres, Luis; Tarrés, Francesc

    2015-01-01

    Automatic summarization generation of sports video content has been object of great interest for many years. Although semantic descriptions techniques have been proposed, many of the approaches still rely on low-level video descriptors that render quite limited results due to the complexity of the problem and to the low capability of the descriptors to represent semantic content. In this paper, a new approach for automatic highlights summarization generation of soccer videos using audio-visual descriptors is presented. The approach is based on the segmentation of the video sequence into shots that will be further analyzed to determine its relevance and interest. Of special interest in the approach is the use of the audio information that provides additional robustness to the overall performance of the summarization system. For every video shot a set of low and mid level audio-visual descriptors are computed and lately adequately combined in order to obtain different relevance measures based on empirical knowledge rules. The final summary is generated by selecting those shots with highest interest according to the specifications of the user and the results of relevance measures. A variety of results are presented with real soccer video sequences that prove the validity of the approach.

  20. Ears on the hand: reaching 3D audio targets

    Directory of Open Access Journals (Sweden)

    Hanneton Sylvain

    2011-12-01

    Full Text Available We studied the ability of right-handed participants to reach 3D audio targets with their right hand. Our immersive audio environment was based on the OpenAL library and Fastrak magnetic sensors for motion capture. Participants listen the target through a “virtual” listener linked to a sensor fixed either on the head or on the hand. We compare three experimental conditions in which the virtual listener is on the head, on the left hand, and on the right hand (that reach the target. We show that (1 participants are able to learn the task but (2 with a low success rate and high durations, (3 the individual levels of performance are very variable, (4 the best performances are achieved when the listener is on the right hand. Consequently, we concluded that our participants were able to learn to locate 3D audio sources even if their ears are transposed on their hand, but we found of behavioral differences between the three experimental conditions.

  1. PESC '82; Annual Power Electronics Specialists Conference, 13th, Massachusetts Institute of Technology, Cambridge, MA, June 14-17, 1982, Record

    Science.gov (United States)

    Aspects of power electronics are addressed. The general topics discussed include: inverters and converters, modelling and analysis, motor drives, power conditioning appliances, power semiconductor devices, and power components and protection. Individual subjects considered include: dual-mode forward/flyback converter; a solar cell power supply system using a boost-type bidirectional DC-DC converter; complete DC analysis of the series resonant converter; variable structure control with sliding mode for DC drive speed regulation; a low-cost single-phase induction generator. Also covered are: small-signal modelling of a push-pull current-fed converter; programmable power processor for high-power space applications; high efficiency 3kW switch mode battery charger; comparison of BIMOS device types; power MOSFET temperature measurements; protection of power transistors in electric vehicle drives; general purpose variable frequency inverter using integrated power modules and LSI. For individual items see A84-18377 to A84-18408

  2. Real-Time Transmission and Storage of Video, Audio, and Health Data in Emergency and Home Care Situations

    Directory of Open Access Journals (Sweden)

    Riccardo Stagnaro

    2007-01-01

    Full Text Available The increase in the availability of bandwidth for wireless links, network integration, and the computational power on fixed and mobile platforms at affordable costs allows nowadays for the handling of audio and video data, their quality making them suitable for medical application. These information streams can support both continuous monitoring and emergency situations. According to this scenario, the authors have developed and implemented the mobile communication system which is described in this paper. The system is based on ITU-T H.323 multimedia terminal recommendation, suitable for real-time data/video/audio and telemedical applications. The audio and video codecs, respectively, H.264 and G723.1, were implemented and optimized in order to obtain high performance on the system target processors. Offline media streaming storage and retrieval functionalities were supported by integrating a relational database in the hospital central system. The system is based on low-cost consumer technologies such as general packet radio service (GPRS and wireless local area network (WLAN or WiFi for lowband data/video transmission. Implementation and testing were carried out for medical emergency and telemedicine application. In this paper, the emergency case study is described.

  3. Real-Time Transmission and Storage of Video, Audio, and Health Data in Emergency and Home Care Situations

    Science.gov (United States)

    Barbieri, Ivano; Lambruschini, Paolo; Raggio, Marco; Stagnaro, Riccardo

    2007-12-01

    The increase in the availability of bandwidth for wireless links, network integration, and the computational power on fixed and mobile platforms at affordable costs allows nowadays for the handling of audio and video data, their quality making them suitable for medical application. These information streams can support both continuous monitoring and emergency situations. According to this scenario, the authors have developed and implemented the mobile communication system which is described in this paper. The system is based on ITU-T H.323 multimedia terminal recommendation, suitable for real-time data/video/audio and telemedical applications. The audio and video codecs, respectively, H.264 and G723.1, were implemented and optimized in order to obtain high performance on the system target processors. Offline media streaming storage and retrieval functionalities were supported by integrating a relational database in the hospital central system. The system is based on low-cost consumer technologies such as general packet radio service (GPRS) and wireless local area network (WLAN or WiFi) for lowband data/video transmission. Implementation and testing were carried out for medical emergency and telemedicine application. In this paper, the emergency case study is described.

  4. Hysteresis controller with constant switching frequency

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2005-01-01

    Switch mode audio power amplifiers are showing up on market in still greater numbers because of advantages in form of high efficiency and low total system cost, especially for high power amplifiers. Several different modulator topologies have been made, ranging from standard PWM to various self......-oscillating and digital modulators. Performance in terms of low distortion, noise and dynamic range differs significantly with the modulator topology used. Highest system performance is generally achieved with analog modulators made as a modulator loop including at least the power stage of the amplifier, because...... of benefits from continuous time operation and non-quantized resolution. This type of modulator uses no external carrier signal, and is called self-oscillating modulators. The work presented in this paper refers to switch mode audio power amplifier, but can be used within a wide range of DC-DC or DC...

  5. An integrated audio-visual impact tool for wind turbine installations

    International Nuclear Information System (INIS)

    Lymberopoulos, N.; Belessis, M.; Wood, M.; Voutsinas, S.

    1996-01-01

    An integrated software tool was developed for the design of wind parks that takes into account their visual and audio impact. The application is built on a powerful hardware platform and is fully operated through a graphic user interface. The topography, the wind turbines and the daylight conditions are realised digitally. The wind park can be animated in real time and the user can take virtual walks in it while the set-up of the park can be altered interactively. In parallel, the wind speed levels on the terrain, the emitted noise intensity, the annual energy output and the cash flow can be estimated at any stage of the session and prompt the user for rearrangements. The tool has been used to visually simulate existing wind parks in St. Breok, UK and Andros Island, Greece. The results lead to the conclusion that such a tool can assist to the public acceptance and licensing procedures of wind parks. (author)

  6. A digital input class-D audio amplifier with sixth-order PWM

    Science.gov (United States)

    Shumeng, Luo; Dongmei, Li

    2013-11-01

    A digital input class-D audio amplifier with a sixth-order pulse-width modulation (PWM) modulator is presented. This modulator moves the PWM generator into the closed sigma—delta modulator loop. The noise and distortions generated at the PWM generator module are suppressed by the high gain of the forward loop of the sigma—delta modulator. Therefore, at the output of the modulator, a very clean PWM signal is acquired for driving the power stage of the class-D amplifier. A sixth-order modulator is designed to balance the performance and the system clock speed. Fabricated in standard 0.18 μm CMOS technology, this class-D amplifier achieves 110 dB dynamic range, 100 dB signal-to-noise rate, and 0.0056% total harmonic distortion plus noise.

  7. High Efficient CMOS Class-E Power Amplifier with a New Output Power Control Scheme

    Directory of Open Access Journals (Sweden)

    MESHKIN Reza

    2013-05-01

    Full Text Available This paper presents the design of a novel RF power amplifier (PA with a new output power control scheme suitable for RF-ICs and portable systems. Employing a class-E amplifier as a drivertogether with soft-switching property of the main power stage switching mode class-E PA helps to achieve better efficiency and increases the capability of circuit integration. A new circuit scheme for efficient output power control is introduced in the proposed PAbased on the array of switches and compensated shunt capacitors with different sizes. This technique improves the Power-Added-Efficiency (PAE and its drop specially at lower output power levels in comparison with conventional power control methods. The layoutof the designed PA is made in 0.18um 1P6M CMOS process, and the chip area is 1.7mm2. simulation results show that the designed PA delivers 21.09dBm output power to a 50 standard load from a 1.8V supply voltage at 2.4GHz operating frequency with 57% PAE. Additionally, the output power of the PA is controlled with steps of 1-dBm by using the proposed array of switches and capacitors.

  8. Audio-Visual Temporal Recalibration Can be Constrained by Content Cues Regardless of Spatial Overlap.

    Science.gov (United States)

    Roseboom, Warrick; Kawabe, Takahiro; Nishida, Shin'ya

    2013-01-01

    It has now been well established that the point of subjective synchrony for audio and visual events can be shifted following exposure to asynchronous audio-visual presentations, an effect often referred to as temporal recalibration. Recently it was further demonstrated that it is possible to concurrently maintain two such recalibrated estimates of audio-visual temporal synchrony. However, it remains unclear precisely what defines a given audio-visual pair such that it is possible to maintain a temporal relationship distinct from other pairs. It has been suggested that spatial separation of the different audio-visual pairs is necessary to achieve multiple distinct audio-visual synchrony estimates. Here we investigated if this is necessarily true. Specifically, we examined whether it is possible to obtain two distinct temporal recalibrations for stimuli that differed only in featural content. Using both complex (audio visual speech; see Experiment 1) and simple stimuli (high and low pitch audio matched with either vertically or horizontally oriented Gabors; see Experiment 2) we found concurrent, and opposite, recalibrations despite there being no spatial difference in presentation location at any point throughout the experiment. This result supports the notion that the content of an audio-visual pair alone can be used to constrain distinct audio-visual synchrony estimates regardless of spatial overlap.

  9. Audio-visual temporal recalibration can be constrained by content cues regardless of spatial overlap

    Directory of Open Access Journals (Sweden)

    Warrick eRoseboom

    2013-04-01

    Full Text Available It has now been well established that the point of subjective synchrony for audio and visual events can be shifted following exposure to asynchronous audio-visual presentations, an effect often referred to as temporal recalibration. Recently it was further demonstrated that it is possible to concurrently maintain two such recalibrated, and opposing, estimates of audio-visual temporal synchrony. However, it remains unclear precisely what defines a given audio-visual pair such that it is possible to maintain a temporal relationship distinct from other pairs. It has been suggested that spatial separation of the different audio-visual pairs is necessary to achieve multiple distinct audio-visual synchrony estimates. Here we investigated if this was necessarily true. Specifically, we examined whether it is possible to obtain two distinct temporal recalibrations for stimuli that differed only in featural content. Using both complex (audio visual speech; Experiment 1 and simple stimuli (high and low pitch audio matched with either vertically or horizontally oriented Gabors; Experiment 2 we found concurrent, and opposite, recalibrations despite there being no spatial difference in presentation location at any point throughout the experiment. This result supports the notion that the content of an audio-visual pair can be used to constrain distinct audio-visual synchrony estimates regardless of spatial overlap.

  10. Switching power amplifier for TAR3

    OpenAIRE

    Moore, Eric Wesley

    1995-01-01

    This thesis describes the theory, design, construction, and testing of a switching power amplifier. The major emphasis of the research and development effort reported herein is to design and construct an efficient power amplifier for varying load conditions which provides 40 Watts of power, at 85% efficiency, and with no more than 10% harmonic distortion. The power amplifier will need one voltage supply and one input audio signal. The amplifier will be used to power demonstration thermoacoust...

  11. Music and audio - oh how they can stress your network

    Science.gov (United States)

    Fletcher, R.

    Nearly ten years ago a paper written by the Audio Engineering Society (AES)[1] made a number of interesting statements: 1. 2. The current Internet is inadequate for transmitting music and professional audio. Performance and collaboration across a distance stress beyond acceptable bounds the quality of service Audio and music provide test cases in which the bounds of the network are quickly reached and through which the defects in a network are readily perceived. Given these key points, where are we now? Have we started to solve any of the problems from the musician's point of view? What is it that musician would like to do that can cause the network so many problems? To understand this we need to appreciate that a trained musician's ears are extremely sensitive to very subtle shifts in temporal materials and localisation information. A shift of a few milliseconds can cause difficulties. So, can modern networks provide the temporal accuracy demanded at this level? The sample and bit rates needed to represent music in the digital domain is still contentious, but a general consensus in the professional world is for 96 KHz and IEEE 64-bit floating point. If this was to be run between two points on the network across 24 channels in near real time to allow for collaborative composition/production/performance, with QOS settings to allow as near to zero latency and jitter, it can be seen that the network indeed has to perform very well. Lighting the Blue Touchpaper for UK e-Science - Closing Conference of ESLEA Project The George Hotel, Edinburgh, UK 26-28 March, 200

  12. The complete guide to high-end audio

    CERN Document Server

    Harley, Robert

    2015-01-01

    An updated edition of what many consider the "bible of high-end audio"   In this newly revised and updated fifth edition, Robert Harley, editor in chief of the Absolute Sound magazine, tells you everything you need to know about buying and enjoying high-quality hi-fi. With this book, discover how to get the best sound for your money, how to identify the weak links in your system and upgrade where it will do the most good, how to set up and tweak your system for maximum performance, and how to become a more perceptive and appreciative listener. Just a few of the secrets you will learn cover hi

  13. Synthesis of audio spectra using a diffraction model.

    Science.gov (United States)

    Vijayakumar, V; Eswaran, C

    2006-12-01

    It is shown that the intensity variations of an audio signal in the frequency domain can be obtained by using a mathematical function containing a series of weighted complex Bessel functions. With proper choice of values for two parameters, this function can transform an input spectrum of discrete frequencies of unit intensity into the known spectra of different musical instruments. Specific examples of musical instruments are considered for evaluating the performance of this method. It is found that this function yields musical spectra with a good degree of accuracy.

  14. Tools for signal compression applications to speech and audio coding

    CERN Document Server

    Moreau, Nicolas

    2013-01-01

    This book presents tools and algorithms required to compress/uncompress signals such as speech and music. These algorithms are largely used in mobile phones, DVD players, HDTV sets, etc. In a first rather theoretical part, this book presents the standard tools used in compression systems: scalar and vector quantization, predictive quantization, transform quantization, entropy coding. In particular we show the consistency between these different tools. The second part explains how these tools are used in the latest speech and audio coders. The third part gives Matlab programs simulating t

  15. Quantitative characterisation of audio data by ordinal symbolic dynamics

    Science.gov (United States)

    Aschenbrenner, T.; Monetti, R.; Amigó, J. M.; Bunk, W.

    2013-06-01

    Ordinal symbolic dynamics has developed into a valuable method to describe complex systems. Recently, using the concept of transcripts, the coupling behaviour of systems was assessed, combining the properties of the symmetric group with information theoretic ideas. In this contribution, methods from the field of ordinal symbolic dynamics are applied to the characterisation of audio data. Coupling complexity between frequency bands of solo violin music, as a fingerprint of the instrument, is used for classification purposes within a support vector machine scheme. Our results suggest that coupling complexity is able to capture essential characteristics, sufficient to distinguish among different violins.

  16. Digital video and audio broadcasting technology a practical engineering guide

    CERN Document Server

    Fischer, Walter

    2010-01-01

    Digital Video and Audio Broadcasting Technology - A Practical Engineering Guide' deals with all the most important digital television, sound radio and multimedia standards such as MPEG, DVB, DVD, DAB, ATSC, T-DMB, DMB-T, DRM and ISDB-T. The book provides an in-depth look at these subjects in terms of practical experience. In addition it contains chapters on the basics of technologies such as analog television, digital modulation, COFDM or mathematical transformations between time and frequency domains. The attention in the respective field under discussion is focussed on aspects of measuring t

  17. Using Audio-Derived Affective Offset to Enhance TV Recommendation

    DEFF Research Database (Denmark)

    Shepstone, Sven Ewan; Tan, Zheng-Hua; Jensen, Søren Holdt

    2014-01-01

    . First a user's mood profile is determined using 12-class audio-based emotion classifications . An initial TV content item is then displayed to the user based on the extracted mood profile. The user has the option to either accept the recommendation, or to critique the item once or several times......, by navigating the emotion space to request an alternative match. The final match is then compared to the initial match, in terms of the difference in the items' affective parameterization . This offset is then utilized in future recommendation sessions. The system was evaluated by eliciting three different...

  18. Utilizing Domain Knowledge in End-to-End Audio Processing

    DEFF Research Database (Denmark)

    Tax, Tycho; Antich, Jose Luis Diez; Purwins, Hendrik

    2017-01-01

    End-to-end neural network based approaches to audio modelling are generally outperformed by models trained on high-level data representations. In this paper we present preliminary work that shows the feasibility of training the first layers of a deep convolutional neural network (CNN) model...... to learn the commonly-used log-scaled mel-spectrogram transformation. Secondly, we demonstrate that upon initializing the first layers of an end-to-end CNN classifier with the learned transformation, convergence and performance on the ESC-50 environmental sound classification dataset are similar to a CNN...

  19. MP3 audio-editing software for the department of radiology

    International Nuclear Information System (INIS)

    Hong Qingfen; Sun Canhui; Li Ziping; Meng Quanfei; Jiang Li

    2006-01-01

    Objective: To evaluate the MP3 audio-editing software in the daily work in the department of radiology. Methods: The audio content of daily consultation seminar, held in the department of radiology every morning, was recorded and converted into MP3 audio format by a computer integrated recording device. The audio data were edited, archived, and eventually saved in the computer memory storage media, which was experimentally replayed and applied in the research or teaching. Results: MP3 audio-editing was a simple process and convenient for saving and searching the data. The record could be easily replayed. Conclusion: MP3 audio-editing perfectly records and saves the contents of consultation seminar, and has replaced the conventional hand writing notes. It is a valuable tool in both research and teaching in the department. (authors)

  20. WebGL and web audio software lightweight components for multimedia education

    Science.gov (United States)

    Chang, Xin; Yuksel, Kivanc; Skarbek, Władysław

    2017-08-01

    The paper presents the results of our recent work on development of contemporary computing platform DC2 for multimedia education usingWebGL andWeb Audio { the W3C standards. Using literate programming paradigm the WEBSA educational tools were developed. It offers for a user (student), the access to expandable collection of WEBGL Shaders and web Audio scripts. The unique feature of DC2 is the option of literate programming, offered for both, the author and the reader in order to improve interactivity to lightweightWebGL andWeb Audio components. For instance users can define: source audio nodes including synthetic sources, destination audio nodes, and nodes for audio processing such as: sound wave shaping, spectral band filtering, convolution based modification, etc. In case of WebGL beside of classic graphics effects based on mesh and fractal definitions, the novel image processing analysis by shaders is offered like nonlinear filtering, histogram of gradients, and Bayesian classifiers.