New proposal of sound absorption coefficient measurement method using a parametric speaker and microphones

Abstract

In recent years, a method for measuring sound absorption coefficient by parametric speakers has been proposed. In previous study, we proposed a method using particle velocity sensors for this measurement, but it was an expensive method. Therefore, in this study, as a new method for measuring sound absorption coefficient using inexpensive microphone, we propose to derive the sound absorption coefficient from the sound pressure of ultrasound at two points and the sound pressure of audible sound at one point of a parametric speaker. The width of the microphone used to measure the sound pressure is taken into account. Then, the validity of the proposed method is confirmed by numerical calculations.