Speech detection enhancement in optical fiber acoustic sensor via adaptive threshold function

Abstract

Abstract In this paper, we demonstrate a novel speech enhancement method for improving detection performance of optical fiber acoustic sensor. The proposed method is based on a novel threshold function with adaptive threshold for wavelet analysis. For a certain speech signal, the adaptive threshold in the function is set lower in speech presence region and higher in speech absence region, which ensures more speech details preserved as well as noise reduced. At the same time, the new threshold function guarantees the continuity and no deviation of speech signal. Experimental results show that the proposed method is more suitable for optical fiber acoustic sensor to extract speech signal compared with universal wavelet packet method, and it improves speech quality significantly. The clear speech can be obtained via the optical fiber acoustic sensor even if work surroundings of sensing unit is noisy.