Background Noise Effects on the Measurement of Sound Power of Small Machines Using Sound Intensity Techniques

This paper reports on an investigation into the effects of varying amounts of background noise on sound power measurements using the two microphone sound intensity approach. Two sets of measurements were taken on machine sources; one set at a distance of approximately 0.5m and the other very close to the sources. Results show that the sound intensity method is a viable technique for measuring the sound power of a source and that indicators can be obtained which show when sound power results are unreliable.