# Mode Domain Spatial Active Noise Control Using Sparse Signal Representation

## TL;DR

This paper introduces a mode-domain active noise control method that uses sparse signal representation to effectively reduce noise over large spaces with fewer microphones, outperforming traditional approaches.

## Contribution

It proposes a novel mode-domain ANC approach utilizing sparse signal representation to decrease microphone count and enhance noise attenuation over large areas.

## Key findings

- Effective noise reduction above the spatial Nyquist frequency.
- Reduced microphone requirement without sacrificing performance.
- Superior noise attenuation compared to conventional methods.

## Abstract

Active noise control (ANC) over a sizeable space requires a large number of reference and error microphones to satisfy the spatial Nyquist sampling criterion, which limits the feasibility of practical realization of such systems. This paper proposes a mode-domain feedforward ANC method to attenuate the noise field over a large space while reducing the number of microphones required. We adopt a sparse reference signal representation to precisely calculate the reference mode coefficients. The proposed system consists of circular reference and error microphone arrays, which capture the reference noise signal and residual error signal, respectively, and a circular loudspeaker array to drive the anti-noise signal. Experimental results indicate that above the spatial Nyquist frequency,our proposed method can perform well compared to a conventional methods. Moreover, the proposed method can even reduce the number of reference microphones while achieving better noise attenuation.