ETS-Lindgren's Acoustic Reverberation Chambers reflect sounds to produce a non-directional or diffuse sound field within the chamber. They are typically used for sound absorption, transmission loss, and sound power measurements. Unlike the sound pressure level produced by a device, the sound power level is a property of the device and is independent of the test environment. Reverberation chambers are also used to measure the sound absorption characteristics of materials or other items such as soft panels, screens or pieces of furniture (e.g. theater seats, chairs, and sofas). These chambers provide a diffuse-field environment that enables sound absorption tests, sound power tests, and transmission loss studies to be performed.