Joe Bloggs

Chief of Testing


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Reverberation chambers

A reverberation chamber has hard surfaces which reflect sound. The sound from a machine or other noise source is reflected many times to produce a non-directional or ‘diffuse’ sound field within the chamber. The sound power emitted from a machine can then be determined from the sound level in the chamber and from the characteristics of the room such as its volume, surface area and reverberation time. Unlike the sound pressure level produced by a machine or piece of equipment, the sound power level is a property of the machine and is independent of the test environment.

A reverberation chamber is also used to measure the sound absorption of acoustic materials, soft panels or screens, and items of furniture for example theatre seats, office desks and chairs, etc.

A reverberation chamber enables us to generate high-intensity diffuse noise fields for acoustic fatigue testing of, for example, spacecraft and aircraft components. These components must be able to withstand high levels of noise without noise-induced vibration causing wiring or circuit boards to fail.

Large Reverberation Chamber

The Large Reverberation Chamber at the ISVR


Built as a box within a box and isolated from the surrounding building.
The internal surfaces are finished with a hard gloss paint to give a high reflection coefficient.


Non-parallel walls, mean edge lengths 9.15 m × 6.25 m × 6.10 m high.
Volume 348 cubic metres. Surface area 302 square metres.


Double doors 1.98 m wide × 2.42 m high.
2.02 m × 2.42 m interconnecting doorway / test aperture to small chamber.

Small Reverberation Chamber


This chamber is of similar construction to the Large Reverberation Chamber.


Non-parallel walls, mean edge lengths 6.40 m × 4.60 m × 4.30 m
Volume 131 cubic metres. Surface Area 153 square metres

Transmission Suite

The Large and the Small Reverberation Chambers may be used together to measure transmission losses of wall, panel or glazing samples up to 2.0 m × 2.4 m. Similarly, the Large Anechoic and Small Reverberant Chambers may be used where diffuse to free field (or vice versa) testing is required.

User’s guide to the test facilities

We have produced a brief guide to the ISVR Rayleigh Laboratory test facilities. It can be downloaded and printed. It gives a description of the facilities, including the Reverberation Chambers, with photographs showing access routes and dimensions.  The guide is intended to assist clients wishing to test large pieces of equipment.  Download guide to test facilities in pdf format (316 KB).