Determination of radiated sound power from acoustic sources using the VBSP method and a mylar boundary

The development of an “acoustic tent” for measuring the radiated sound power from devices with complex or hidden geometries using a vibration-based sound power (VBSP) method is presented. The VBSP method is based on spatially dense velocity measurements of the vibrating structure and has previously been validated for flat plates, cylindrical-shells, simple-curved panels, and arbitrarily curved panels. However, many acoustic sources, such as electric drone motors, kitchen appliances, and vehicles have sound power contributions from components where the velocity is difficult to measure. To overcome this challenge, a rectangular box with four high impedance walls, one rigid side, and one thin mylar side was used to enclose the noise source, forming an acoustic tent around the device. The acoustic tent was able to be calibrated to within 1-3 dB of the free-field sound power measurements for several different sources. Limitations of the VBSP acoustic tent are also presented and discussed.