Improved in-car sound pick-up using multichannel Wiener filter

TL;DR

This paper demonstrates that using a multichannel Wiener filter with two microphones in a car significantly improves speech quality by reducing echoes and background noise, enhancing hands-free communication.

Contribution

It introduces the application of the Multichannel Wiener Filter in in-car systems and evaluates its effectiveness under various noise and movement conditions.

Findings

Significant noise reduction and echo mitigation achieved.

Improved speech quality measured by objective metrics.

Robustness to head movements demonstrated.

Abstract

With advancements in automotive electronics and sensors, the sound pick-up using multiple microphones has become feasible for hands-free telephony and voice command in-car applications. However, challenges remain in effectively processing multiple microphone signals due to bandwidth or processing limitations. This work explores the use of the Multichannel Wiener Filter algorithm with a two-microphone in-car system, to enhance speech quality for driver and passenger voice, i.e., to mitigate notch-filtering effects caused by echoes and improve background noise reduction. We evaluate its performance under various noise conditions using modern objective metrics like Deep Noise Suppression Mean Opinion Score. The effect of head movements of driver/passenger is also investigated. The proposed method is shown to provide significant improvements over a simple mixing of microphone signals.