Anechoic Chamber
The anechoic chamber is an experimental space which, thanks to its sound-absorbing materials, is entirely free from room acoustics.

© Sergio Grazia
The anechoic chamber is an experimental space which, thanks to its sound-absorbing materials, is entirely free from room acoustics.

© Sergio Grazia
An anechoic chamber is a room for acoustic experiments that absorbs as much sound as possible. The ceiling, floor and walls are covered with fiberglass wedge-shaped panels that absorb almost all the acoustic energy. Therefore the sound propagates in space without reflections, a situation that artificially recreates what physicians call "free field conditions".
The anechoic chamber is used primarily to measure the radiation characteristics of sound sources. Numerous studies have shown that the radiation patterns of natural sound sources vary with frequency and time. If we use the example of a musical instrument, its radiated acoustic field depends on the note played, on the type of instrument, and other parameters. To measure radiation patterns, it is necessary to separate the direct field radiated by the instrument and the field reflected by the room's surfaces. In an anechoic situation the reflected acoustic energy is negligible and thus only the free-field radiation is measured. The anechoic chamber is also used as a "quiet" room. Measuring very precise sounds necessitates a very low recording level, without any background noise. Extremely well isolated from the outside and the rest of the building (a sort of a box in a box mounted on neoprene silent blocks), this room makes it possible to have a satisfactory signal/noise relationship.