Biennial on Digital Signal Processing for In-Vehicle and Mobile Systems Sesimbra, Portugal September 2-3, 2005

ICA-based Technique in Air and Bone-Conductive Microphones for Speech Enhancement

Zhipeng Zhang, Kei Kikuiri, Nobuhiko Naka, Tomoyuki Ohya

Multimedia Laboratories, NTT DoCoMo, Yokosuka, Kanagawa, Japan

How to obtain clean speech signal in noisy environments is a crucial issue for improving the appeal of mobile phones. This paper proposes to supplement the existing normal air-conductive microphone with a bone-conductive microphone for noise reduction. We propose to apply the ICA (Independent Component Analysis)- based technique to the air and bone-conductive microphone combination for speech enhancement. The speech signal output by the bone-conductive microphone has the advantage of very high SNR, which well supports the generation of a clean speech signal in combination with a normal microphone. We evaluate this method by a Japanese digital recognition system. The results confirm that the proposed method can allow a mobile phone to obtain a clean speech signal even if the background noise is relatively high.

Bibliographic reference.  Zhang, Zhipeng / Kikuiri, Kei / Naka, Nobuhiko / Ohya, Tomoyuki (2005): "ICA-based technique in air and bone-conductive microphones for speech enhancement", In DSP-in-V-2005, paper M2-11 (abstract).