A note on the audio sound power generated by a parametric array loudspeaker

Understanding the sound power characteristics of parametric array loudspeakers (PALs) poses a unique challenge due to the nonlinear process involved. This work addresses this issue by employing the spherical convolution directivity model to obtain the far field intensity, which is then used to calculate the sound power radiated by a PAL. The results reveal that the audio sound power is approximately proportional to the square of the audio frequency and the aperture size, while inversely proportional to the ultrasound frequency. Additionally, the conversion efficiency from ultrasound to audio sound is found to be generally below 0.15% for typical configurations.