Unvoiced Speech Recognition Using Tissue-Conductive Acoustic Sensor

Autor: Hiroshi Saruwatari, Kiyohiro Shikano, Tomomi Kaino, Panikos Heracleous
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Zdroj: EURASIP Journal on Advances in Signal Processing, Vol 2007 (2007)
Druh dokumentu: article
ISSN: 1687-6172
1687-6180
DOI: 10.1155/2007/94068
Popis: We present the use of stethoscope and silicon NAM (nonaudible murmur) microphones in automatic speech recognition. NAM microphones are special acoustic sensors, which are attached behind the talker's ear and can capture not only normal (audible) speech, but also very quietly uttered speech (nonaudible murmur). As a result, NAM microphones can be applied in automatic speech recognition systems when privacy is desired in human-machine communication. Moreover, NAM microphones show robustness against noise and they might be used in special systems (speech recognition, speech transform, etc.) for sound-impaired people. Using adaptation techniques and a small amount of training data, we achieved for a 20 k dictation task a 93.9% word accuracy for nonaudible murmur recognition in a clean environment. In this paper, we also investigate nonaudible murmur recognition in noisy environments and the effect of the Lombard reflex on nonaudible murmur recognition. We also propose three methods to integrate audible speech and nonaudible murmur recognition using a stethoscope NAM microphone with very promising results.
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