An acoustic anechoic chamber is a room in which there are no echoes. Used to test and determine the noise decibel ratings for products such as fan for computer, power supply etc. Anechoic chambers are commonly used in acoustics to perform experiments in nominally free field conditions. This means that all sound energywill be traveling away from the source with almost none being reflected back. Common anechoic chamber experiments include measuring thetransfer function of a loudspeaker or the directivity of noise radiation from industrial machinery.
Anechoic chambers are also generally very quietchambers, with typical noise levels in the 10-20 dBA range.