Interspeech'2005 - Eurospeech

Lisbon, Portugal
September 4-8, 2005

Applications of NAM Microphones in Speech Recognition for Privacy in Human-Machine Communication

Panikos Heracleous, Tomomi Kaino, Hiroshi Saruwatari, Kiyohiro Shikano

Nara Institute of Science and Technology, Japan

In this paper, we present the use of stethoscope and silicon NAM 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 (non-audible murmur). As a result, NAM microphones can be applied in automatic speech recognition systems when privacy is desired. Previously, we presented speech recognition experiments for non-audible murmur captured by a stethoscope microphone. In this paper, we also present recognition results using a more advanced NAM microphone, the so-called silicon NAM microphone. Using adaptation techniques and a small amount of training data, we achieved a 93.9% word accuracy for non-audible murmur recognition. We also report experimental results in noisy environments showing the effectiveness of using a NAM microphone in noisy environments. In addition to a dictation task, we also present a keyword spotting experiment based on non-audible murmur.

Full Paper

Bibliographic reference.  Heracleous, Panikos / Kaino, Tomomi / Saruwatari, Hiroshi / Shikano, Kiyohiro (2005): "Applications of NAM microphones in speech recognition for privacy in human-machine communication", In INTERSPEECH-2005, 3041-3044.