Theoretical and Experimental Comparison of Amplitude Modulation Techniques for Parametric Loudspeakers
Due to the self-demodulation property of finite amplitude ultrasonic waves propagating in air, a highly focused sound beam can be reproduced. This phenomenon is known as the parametric array in air. However, because of the nonlinearity effect of ultrasonic waves, the reproduced sound wave suffers from high distortion. Several amplitude modulation techniques have been previously proposed to mitigate this problem. Currently, no comprehensive study has been carried out to evaluate the performance of these amplitude modulation techniques. This paper attempts to provide theoretical and experimental studies of the effectiveness in mitigating the distortion from different amplitude modulation techniques. Objective measurements, such as sound pressure level and total harmonic distortion are used to compare the performance of these modulation techniques.
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members and is temporarily free for AES members.