WordNet
n. a chamber having very little reverberation
Wikipedia
An anechoic chamber ("an-echoic" meaning non-reflective, non-echoing or echo-free) is a room designed to completely absorb reflections of either sound or electromagnetic waves. They are also insulated from exterior sources of noise. The combination of both aspects means they simulate a quiet open-space of infinite dimension, which is useful when exterior influences would otherwise give false results.
Anechoic chambers, a term coined by American acoustics expert Leo Beranek, were originally used in the context of acoustics ( sound waves) to minimize the reflections of a room. More recently, rooms designed to reduce reflection and external noise in radio frequencies have been used to test antennas, radars, or electromagnetic interference.
Anechoic chambers range from small compartments the size of household microwave ovens to ones as large as aircraft hangars. The size of the chamber depends on the size of the objects to be tested and the frequency range of the signals used, although scale models can sometimes be used by testing at shorter wavelengths (higher frequencies).
Usage examples of "anechoic chamber".
At night there might have been the whine of insects, but they were deep under the sand against the scorch of day, and the yellow sky and yellow sand became an anechoic chamber in which You Bastard's breath sounded like a steam-engine.
At night there might have been the whine of insects, but they were deep under the sand against the scorch of day, and the yellow sky and yellow sand became an anechoic chamber in which You Bastard’.