Sound power estimation with an acoustic camera in comparison with sound power determination using sound pressure and sound intensity method

Abstract

Sound Power Level (SWL) is a measure to be used to describe a sound source regardless its surrounding and environment. In general, there are two different standardized methods to determine the Sound Power Level of a sound source, which are by using sound pressure and sound intensity. Other than that, there is a possibility to estimate Sound Power Level using an acoustic beamforming array or more popularly known as acoustic camera. This estimation is considered more time-efficient compared to the two methods and can be done when there are other sound sources during the measurement. However, this measurement is not yet standard compliant and therefore cannot be used for standardized reporting or legislative purposes. The paper highlights the possibility to estimate Sound Power Level of a Reference Sound Source using an acoustic beamforming array, when another sound source is present at the time of measurement. Besides comparing to the Reference Sound Source's calibration chart, the measurement is compared with two ISO-compliant measurements which are ISO 3746 (Survey grade, sound pressure method) and ISO 9614-2 (survey grade, sound intensity method).