A cylindrical expansion of the audio sound for a steerable parametric array loudspeaker

Area of Science:

• Acoustics
• Nonlinear Acoustics
• Array Signal Processing

Background:

• Parametric Array Loudspeakers (PALs) are directional sound sources.
• Accurate modeling of audio sound generation in PALs is crucial for performance optimization.
• Existing models, like the convolution model, face limitations in capturing complex nonlinear near-field interactions.

Purpose of the Study:

• To derive and validate a cylindrical expansion for audio sound generated by steerable baffled parametric array loudspeakers (PALs).
• To provide a more accurate and computationally efficient alternative to existing modeling approaches.
• To improve the agreement between predicted and experimental results for PAL performance.

Main Methods:

• Derivation of a cylindrical expansion from the Westervelt equation for audio sound prediction.
• The expansion involves twofold summations with uncoupled angular and radial components.
• Numerical results were generated for a steerable PAL and compared with the convolution model and experimental data.

Main Results:

• The proposed cylindrical expansion shows improved agreement with experimental results compared to the convolution model.
• The model accurately captures nonlinear near-field interactions without further approximations.
• The cylindrical expansion offers high accuracy at a relatively low computational cost.

Conclusions:

• The derived cylindrical expansion is a viable and accurate alternative for modeling phased array PALs.
• This method overcomes limitations of the convolution model in handling complex nonlinear acoustic phenomena.
• The approach facilitates more precise prediction of audio sound from steerable PALs.