Acoustic Anechoic Chamber
SRI's Sound and Vibration Laboratory uses an acoustic anechoic chamber to make acoustic measurements in a controlled, non-reverberant environment. Located at SRI's Menlo Park, California, headquarters, the chamber is useful for a variety of experimental purposes, including:
- Measuring sound quality
- Measuring response of loudspeakers and other acoustic transducers
- Characterizing properties of acoustic materials
- Controlled listening and speech experiments
The chamber measures 8.6 m x 3.7 m by 2.3 m high and is fully anechoic—all surfaces are treated—with a wire-suspension floor with mount points to support people and equipment loads.
The chamber is equipped for listening experiments and features four high-fidelity, wide-frequency-band loudspeakers to project sound, as well as microphones to measure and record sound. Avid Pro Tools® acoustic software is used to control sources and monitor user inputs during experiments.
The anechoic chamber exceeds ANSI S1.35-1979 standards for acoustic reverberation and NC-10 standards for acoustic isolation. It is anechoic from 100 Hz to 10,000 Hz, and background noise is less than 10 dB SPL.