Sound Power Determination in Reverberation Rooms at Low Frequencies

✍ Scribed by F.T. Agerkvist; F. Jacobsen

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 418 KB
• Volume: 166
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1993.1290

✦ Synopsis

The traditional method of measuring the sound power radiated by a source in a reverberation room is examined theoretically and experimentally with particular regard to low frequencies. This method has for many years been suspected of underestimation at low frequencies. However, this suspicion is not confirmed. The "Waterhouse correction" is shown to be surprisingly accurate even at very low frequencies. It is also shown that the radiated sound power of a monopole source of constant strength with appropriate averaging over source positions equals the free field power of the source. Finally, it is demonstrated that the usual sound power estimate based on measurement of the spatial average of the mean square pressure is unbiased, provided that the losses of the room are deduced from the initial rates of decay.