Performance evaluation of sound absorbing material by parametric speaker

Abstract

In recent years, a method for evaluating the performance of sound absorbing material by parametric speaker has been proposed. However, this evaluation method is limited to experimental research, and sufficient theoretical research has not been conducted. Therefore, in this study, we theoretically examine the 2-microphone method, which is a previous study as a sound absorption coefficient measurement method, when using a parametric speaker. Furthermore, as a new sound absorption performance evaluation method based on this research, the sound absorption coefficient is derived from the sound pressure displacement of two points of ultrasound and one point of sound pressure displacement of audible sound generated from a parametric speaker. Then, the validity of proposed method is confirmed by numerical calculation.