1996 MAY, VOLUME 44 NUMBER 5

PAPERS

Physical Modeling of Plucked String Instruments with Application to Real-Time Sound Synthesis
Vesa Välimäki, Jyri Huopaniemi, Matti Karjalainen, and Zoltán Jánosy p. 331
Real-time sound synthesis has been implemented on five plucked string instruments with the view to extending the techniques to similar instruments. Future studies will include modeling other plucked string instruments, a more sophisticated inverse filtering design to account for the varying decay rates of each harmonic, and a method to estimate the string's plucking point, which is critical to the harmonic content of the sound.

Designing Curved Diffusers for Performance Spaces
Trevor J. Cox p. 354
Design optimization of performance space diffusers generates diffuser shapes that minimize energy distribution variations in the specular zone. These optimized diffusers generally outperform those based on the standard arc of a circle, although in some unbaffled cases the standard curved surface is the better diffuser choice within the optimization domain.

A Microphone Array for Multimedia Workstations
Y. Mahieux, G. Le Tourneur, and A. Saliou p. 365
A controlled microphone array achieves a high directivity index using a cleverly designed transducer arrangement that shapes and controls the beamwidth. The system reduces noise and reverberation, which in a comparison test was preferred by listeners over a single unidirectional microphone tested in the same environment.

An Analysis Procedure for Room Acoustics and Sound Amplification Systems Based on the Early-to-Late Sound Energy Ratio
L. Gerald Marshall p. 373
Analysis of auditorium acoustics is performed using the early-to-late sound energy system. Constants for optimum speech or music are described and the energy-time curves by octave bands are analyzed for reflections in the 200-ms early time period. Software for this analysis system is available.

STANDARDS AND INFORMATION DOCUMENTS

AES20-1996 AES recommended practice for professional audio - Subjective evaluation of loudspeakers p. 382

DRAFT AES28-xxxx, DRAFT AES standard for audio preservation and restoration - Method for estimating life expectancy of compact discs (CD-ROM) based on effects of temperature and relative humidity (insert)

AES Standards Committee News p. 403
Listening-test standard; interconvention SC-10 meetings

FEATURES

Routing MIDI Messages Over Ethernet
Richard Foss and Thabo Mosala p. 406

1996 Directory of Educational Programs (insert)

DEPARTMENTS

Review of Acoustical Patents p. 404
News of the Sections p. 416
Sound Track p. 424
Upcoming Meetings p. 426
New Products and Developments p. 427
Available Literature p. 430
Membership Information p. 432
In Memoriam p. 435
Audio Engineering Society Application Instructions p. 437
AES Special Publications p. 440
Sections Contacts Directory p. 444
AES Conventions and Conferences p. 448