Statistical approaches to enhancement of body-conducted speech detected with non-audible murmur microphone

In this paper, we review our recent research on technologies for enhancing body-conducted speech detected with nonaudible murmur (NAM) microphone. NAM microphone has been developed to detect an extremely soft whispered voice, which is useful for silent speech communication. Moreover, it is also capable of detecting other voices such as a soft voice and a normal voice while effectively reducing external noise owing to its noise-proof structure. On the other hand, speech quality of the detected voices severely degrades by the body-conductive recording. To address this issue, we have developed technologies for statistically converting body-conducted speech into normal speech. This paper gives an overview of these technologies and a further attempt to make it possible to use them for human-to-human speech communication.