An acoustic anechoic chamber is a room designed to be free of reverberation (hence non-echoing or echo-free). The walls, ceiling and floor are usually lined with a sound absorbent material to minimise reflections and insulate the room from exterior sources of noise. All sound energy will travel away from the source with almost none reflected back. Thus a listener within an anechoic chamber will only hear the direct sound, with no reverberation.
The anechoic chamber effectively simulates a quiet open-space of infinite dimension. Thus, they are used to conduct acoustics experiments in ‘free field’ conditions. They are often used to measure the radiation pattern of a microphone or of a noise source, or the transfer function of a loudspeaker.
An anechoic chamber is very quiet, with noise levels typically close to the threshold of hearing in the 10–20 dBA range (the quietest anechoic chamber has a decibel level of…
View original post 224 more words