ESSV Konferenz Elektronische Sprachsignalverarbeitung

Title: Multi-Channel Speech Enhancement for Car Applications

Authors: Huajun Yu, Tim Fingscheidt


Beamforming for car applications has gained much attention in the past. With upcoming wideband speech telephony appropriate solutions operating at a sampling frequency of 16 kHz are required. While a number of proposals aims at quite idealistic conditions, our approach intentionally employs low-cost microphones, and it is optimized and tested with real multi-channel signals acquired using these sensors. Moreover, we assume the microphone array to be integrated into the head-unit of the car. Although from a signal-to-noise ratio perspective this is not an ideal location, it is yet very attractive, since no further wiring is necessary and radio navigation systems manufacturers can offer compact and optimized solutions. To achieve the required level of directivity (and therefore noise reduction) in car noise, we exploit the a priori noise field coherence of diffuse noise. An adaptive smoothing approach for post-filter estimation along with a new combination of the beamformer and the post-filter is proposed well suited for the low-cost microphones. Meanwhile, an intrusive instrumental evaluation methodology will be introduced. We will show that a significant level of noise attenuation can be achieved, while simultaneously the quality of the speech component will be improved compared to the state of the art.

Year: 2009
In session: Signalverarbeitung
Pages: 150 to 157