Simulation results demonstrate microphone calibration requirements for soundfield pickup in higher-order ambisonics, indicating limits on microphone numbers and spacing.
Spherical microphone arrays used for Higher-Order Ambisonics (HOA) spatial soundfield pickup are based on the spherical harmonic decomposition of the sound field at the measurement location. Practical design of spherical microphone arrays is based on limiting the number microphones to a reasonable number (<100) and minimizing spatial aliasing artifacts at higher frequencies due to discrete sampling positions when the average microphone spacing exceeds ½ the acoustic wavelength. These two design objectives lead to a design where the HOA components are formed as estimates of higher-order spatial pressure differentials that are computed at frequencies where the acoustic wavelength is much larger than the size of the array (superdirectionality). It is well known that superdirectional arrays are sensitive to sensor calibration mismatch and self-noise. We will show simulation results for the magnitude and phase matching requirements needed to realize spherical HOA arrays as a function of the frequency, the number of microphones, and the array size.
No takes yet. Share an insight, caveat, or question.
Elko et al. (2025) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: