Synthesis of Volterra filters for the parametric array loudspeaker

Abstract

The ultrasound-to-ultrasound Volterra filter (U2VF), which was previously proposed to represent the nonlinear response of the parametric array loudspeaker (PAL), identifies the PAL as a nonlinear system that uses ultrasonic signals as its input. It has been proven that the U2VF is a more generic model as compared to the audio-to-audio Volterra filter (A2VF), when the modulation method is adaptive or the input is time varying. However, there is no explicit solution to a linearization system based on the U2VF. Therefore, this paper proposes a synthesis method to extract A2VFs from the U2VF based on the parallel cascade structure. The mature technique of building a linearization system based on the A2VF can hence be adapted to consort with the U2VF.