Spatially Selective Active Noise Control Systems

TL;DR

This paper introduces a spatially selective active noise control system that reduces noise only from undesired directions while preserving desired sounds, using a multi-channel microphone array and a novel spatial constraint algorithm.

Contribution

It presents a new multi-channel ANC algorithm that achieves spatial selectivity without reconstructing desired sound, improving noise reduction and robustness over existing methods.

Findings

Effective noise reduction from undesired directions

Preserves desired sound without distortion or latency

Maintains performance under array perturbations

Abstract

Active noise control (ANC) systems are commonly designed to achieve maximal sound reduction regardless of the incident direction of the sound. When desired sound is present, the state-of-the-art methods add a separate system to reconstruct it. This can result in distortion and latency. In this work, we propose a multi-channel ANC system that only reduces sound from undesired directions, and the system truly preserves the desired sound instead of reproducing it. The proposed algorithm imposes a spatial constraint on the hybrid ANC cost function to achieve spatial selectivity. Based on a six-channel microphone array on a pair of augmented eyeglasses, results show that the system minimized only noise coming from undesired directions. The control performance could be maintained even when the array was heavily perturbed. The proposed algorithm was also compared with the existing methods in the literature. Not only did the proposed system provide better noise reduction, but it also required much less effort. The binaural localization cues did not need to be reconstructed since the system preserved the physical sound wave from the desired source.