Speech measurements using a laser Doppler vibrometer sensor: Application to speech enhancement

In this paper, we present a remote speech-measurement system, which utilizes an auxiliary laser Doppler vibrometer (LDV) sensor. When focusing on the larynx, this sensor captures useful speech information at low-frequency regions (up to 1.5-2 kHz), and is shown to be immune to acoustical disturbances. For improved speech enhancement, we propose a new algorithm for efficiently combining the signals from the LDV-based sensor and a standard acoustic sensor. The algorithm includes a pre-filtering process, to suppress impulsive noises that severely degrade the LDV-measured speech, and a soft-decision voice activity detector (VAD) in the time-frequency domain. Experimental results demonstrate the performance of the proposed system in transient noise environments.