ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

2pAA10. Initial tests in AT&T Bell Labs' Varechoic Chamber.

William C. Ward

WARD Lab., 2441 Camino Capitan, Santa Fe, NM 87505

Gary W. Elko

Robert A. Kubli

AT&T Bell Labs., Murray Hill, NJ 07974

W. Craig McDougald

Acoustic Systems, Austin, TX 78764

Results are available for the first measurements in the recently completed Varechoic chamber, a digitally controllable variable acoustics facility at AT&T Bell Laboratories in Murray Hill, NJ. The 118 m[sup 3] (6.7x6.1x2.9 m) room has 368 independently actuated surfaces in the walls, ceiling, and floor. The room boundary conditions can be completely changed in a fraction of a second. This chamber is a unique facility for acoustical measurements, testing of electroacoustic and signal processing systems, perception tests, or for recording. The panels from which it is constructed could be applied in multipurpose rooms, recording studios, or performance spaces. Reverberation time in the 750-Hz octave band is variable from 0.1--1.6 s; this talk will present full 1/3-oct decay rates of the room. Some interesting impulse responses, and comparisons with image model calculations, will also be given.