SHB-AE: Spherical harmonic beamforming based Ambisonics encoding and upscaling method for smartphone microphone array
2026-06-03 • Sound
Sound
AI summaryⓘ
The authors address challenges in recording spatial audio for virtual and augmented reality using smartphones, which have fewer and irregularly placed microphones compared to traditional bulky devices. They propose a new method called SHB-AE that uses beamforming techniques to encode and enhance audio spatial information by working with spherical harmonic functions. Their tests showed that this approach could successfully create high-quality spatial audio up to the fourth order using just four smartphone microphones, even in noisy environments. This means better audio experiences are possible with simpler, more portable equipment.
Spatial audioVirtual reality (VR)Augmented reality (AR)Higher Order Ambisonics (HOA)Spherical microphone array (SMA)Spherical harmonic functionsBeamformingSmartphone microphone array (SPMA)Ambisonics encodingAudio up-scaling
Authors
Yuhuan You, Yufan Qian, Tianshu Qu, Bin Wang, Xueyang Lv
Abstract
With the rapid development of virtual reality (VR) and augmented reality (AR), spatial audio recording and reproduction have gained increasing research interest. Higher Order Ambisonics (HOA) stands out for its adaptability to various playback devices and its ability to integrate head orientation. However, current HOA recordings often rely on bulky spherical microphone arrays (SMA), and portable devices like smartphones are limited by array configuration and number of microphones. We propose SHB-AE, a spherical harmonic beamforming based method for Ambisonics encoding using a smartphone microphone array (SPMA). By designing beamformers for each order of spherical harmonic functions based on the array manifold, the method enables Ambisonics encoding and up-scaling. Validation on a real SPMA and its simulated free-field counterpart in noisy and reverberant conditions showed that the method successfully encodes and up-scales Ambisonics up to the fourth order with just four irregularly arranged microphones.