Motion-Tolerant Beamforming with Deformable Microphone Arrays

TL;DR

This paper explores beamforming techniques for deformable microphone arrays, such as wearable devices, comparing geometry-tracking and time-invariant methods, with experiments demonstrating effectiveness in real-world scenarios.

Contribution

It introduces and evaluates a novel time-invariant beamforming approach suitable for deformable arrays, expanding capabilities for wearable audio applications.

Findings

Time-invariant beamforming performs well with small array motions.

Explicit geometry tracking improves beamforming accuracy.

Experimental validation with wearable microphone arrays in real scenarios.

Abstract

Microphone arrays are usually assumed to have rigid geometries: the microphones may move with respect to the sound field but remain fixed relative to each other. However, many useful arrays, such as those in wearable devices, have sensors that can move relative to each other. We compare two approaches to beamforming with deformable microphone arrays: first, by explicitly tracking the geometry of the array as it changes over time, and second, by designing a time-invariant beamformer based on the second-order statistics of the moving array. The time-invariant approach is shown to be appropriate when the motion of the array is small relative to the acoustic wavelengths of interest. The performance of the proposed beamforming system is demonstrated using a wearable microphone array on a moving human listener in a cocktail-party scenario.