Spherical harmonic beamforming basedAmbisonics encoding and upscaling method for smartphonemicrophone array

Citation:

You Y, Qian Y, Qu T, Wang B, Lv X. Spherical harmonic beamforming basedAmbisonics encoding and upscaling method for smartphonemicrophone array, in the AES 158th Convention. Warsaw, Poland; 2025:10230.

Date Presented:

22-24, May

摘要:

With the rapid development of virtual reality (VR) and augmented reality (AR), spatial audio recording and reproductionhave gained increasing research interest. Higher Order Ambisonics (HOA) stands out for its adaptabilityto various playback devices and its ability to integrate head orientation. However, current HOA recordings oftenrely on bulky spherical microphone arrays (SMA), and portable devices like smartphones are limited by arrayconfiguration and number of microphones. We propose SHB-AE, a spherical harmonic beamforming based methodfor Ambisonics encoding using a smartphone microphone array (SPMA). By designing beamformers for eachorder of spherical harmonic functions based on the array manifold, the method enables Ambisonics encoding andup-scaling. Validation on a real SPMA and its simulated free-field counterpart in noisy and reverberant conditionsshowed that the method successfully encodes and up-scales Ambisonics up to the fourth order with just fourirregularly arranged microphones.