Abstract
Parametric speaker can radiate an audible sound beam with sharp directivity by using the non-linear interaction of ultrasonic waves. This radiated sound has directivity even after being reflected on the wall. In recent years, a sound absorption coefficient measurement method using a parametric speaker has been proposed, and parametric speakers are increasingly being used in acoustic spaces with reflective. When analyzing this sound wave, it is necessary to use discrete analysis method that enable analysis in closed space. Many discrete analyses by using finite difference time domain method have been proposed as analysis methods for parametric speakers, but these methods have problem that the calculation load is heavy. In previous study, we constructed a steady-state response analysis method that can efficiently analyze the audible sound of parametric speakers. The previous method is combined a nonlinear concentrated mass model and a perturbation method. In this report, we expand the previous method and construct the equation of motion described in sound pressure coordinates to reduce the computational load. The effectiveness of proposed method is confirmed by numerical calculation.
