|VOLUME 48 NUMBER 6 2000 JUNE|
Revisiting Algorithms for Predicting the Articulation Loss of Consonants ALcons
Sylvio R. Bistafa and John S. Bradley 531
Algorithms proposed for predicting speech intelligibility that are based on articulation loss of consonants (ALcons) are examined. A simple algorithm, the architectural form of the Peutz equation, is discussed and re-derived using a system to further develop empirical equation forms. It is shown that the speech transmission index (STI) and the useful-to-detrimental sound ratio (U50) speech intelligibility predictions are highly correlated with each other in rooms that have diffuse sound fields and ideal exponential decays. The ALcons algorithms, however, have a tendency to under-predict speech intelligibility as the signal-to-noise ratio decreases.
Interactions in a Multiple-Voice-Coil Digital Loudspeaker
Yaxiong Huang, Simon C. Busbridge, and Peter A. Fryer 545
Motional impedance and mutual coupling in a multiple-coil digital loudspeaker system increase the effective impedance of an individual coil relative to its binary weighting in a seven-bit digital constant-current driver configuration. This places an unreasonably high demand on the output impedance of the constant-current driver unless the loudspeaker's damping is controlled. A shorted turn voice coil can achieve this damping most effectively.
Development of the Wireless "Communications EarPlug" for Application in Military Aviation
Sander J. van Wijngaarden, Evert Agterhuis, and Herman J. M. Steeneken 553
Earplugs fitted with integrated miniature speech transducers have been developed specifically for use in high ambient noise level aircraft communications. The earplugs provide isolation from the local noise, while the miniature transducers provide a reliable intercommunication path for the user. The system's utility is further enhanced by integrating it with a wireless intercommunications interface, free of any cord connections to the aircraft's system.
Electrically Manifested Distortions of Condenser Microphones in Audio Frequency Circuits
Holger Pastillé 559
Distortions originate in condenser microphones from several sources: those which are attributable to the microphone's mechanical and acoustic functions and those which arise from their associated electrical circuitry. An analysis of the electrical design distortion contributions indicate that they are relatively minor in modern condenser microphones which have input resistances on the order of 20 G?. The distortions of acoustical and mechanical origin contribute more to the overall condenser microphone's distortion output than does the electrical circuit's configuration.
STANDARDS AND INFORMATION DOCUMENTS
AES41-2000 AES standard for digital audio - Recoding data set for audio bit-rate reduction 564
AES Standards Committee News Call for comment on revised AES26 audio polarity standard; digitally interfaced microphones; microphone specifications 584
High-Quality Multichannel Audio Coding: Trends and Challenges
Marina Bosi 588
News of the Sections 596
Sound Track 600
Upcoming Meetings 601
New Products and Developments 602
Available Literature 605
Membership Information 606
Advertiser Internet Directory 607
Audio Engineering Society Membership Application Instructions 610
AES Special Publications 613
Sections Contacts Directory 618
AES Conventions and Conferences 624
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VOLUME 48 NUMBER 6 2000 JUNE
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