A robotic system for space-time characterization of parametric acoustic sound sources

Abstract

Parametric acoustic loudspeakers use arrays of ultrasonic transducers to generate audible fields through the non linearities of the propagation medium. Despite being commercially well consolidated, some aspects of the generated audible field still deserve further investigation, This paper describes the acquisition of impulse responses generated by parametric loudspeaker prototypes using an automated system to scan the sound field spatially. The scanning system comprises a 6-degree-of-freedom robotic arm mounted over a linear track for increased spatial coverage. The robot positions the microphone in pre specified locations inside two desired apertures irradiated by the sound source. First, scanning planes parallel to the source axis allows direct visualization of the sound field generated by the source. Second, the scan of a normal plane to the source axis allows future applications using near-field acoustic holography and sound field reconstruction. This work showcases the first steps in implementing such measurements for parametric acoustic loudspeakers