Harmonicity-Based Blind Dereverberation for Single-Channel Speech Signals

• Published in: IEEE transactions on audio, speech, and language processing Vol. 15; no. 1; pp. 80 - 95
• Main Authors: Nakatani, T., Kinoshita, K., Miyoshi, M.
• Format: Journal Article
• Language: English
• Published: Piscataway, NJ IEEE 01-01-2007; Institute of Electrical and Electronics Engineers
• Subjects: Acoustics; Acquisitions; Adaptive harmonic filter; Applied sciences; Automatic speech recognition; blind signal processing; Delay effects; dereverberation; Detection, estimation, filtering, equalization, prediction; Estimating; Exact sciences and technology; Filtering; harmonicity; Herbs; Impulse response; Information, signal and communications theory; inverse filter; Marketing; Microphones; Miscellaneous; Nonlinear filters; Reverberation; Signal and communications theory; Signal processing; Signal, noise; Speech; Speech processing; Speech recognition; speech signal; Telecommunications and information theory; Teleconferencing; time warping; Transfer functions; Microphone; Prototype; Warping; blind signal processing; Sound quality; Hand-free system; Artefact; Implementation; Mean square error; speech signal; Accuracy; inverse filter; Reverse filtering; Pulse response; dereverberation; Transfer function; Time analysis; Acoustic signal; Teleconference; Adaptive harmonic filter; Adaptive filter; Reverberation time; Vocal signal; harmonicity; Speech recognition; Band stop filter; time warping; Automatic recognition; Speech processing
• ISSN: 1558-7916; 1558-7924
• DOI: 10.1109/TASL.2006.872620

The distant acquisition of acoustic signals in an enclosed space often produces reverberant artifacts due to the room impulse response. Speech dereverberation is desirable in situations where the distant acquisition of acoustic signals is involved. These situations include hands-free speech recognition, teleconferencing, and meeting recording, to name a few. This paper proposes a processing method, named Harmonicity-based dEReverBeration (HERB), to reduce the amount of reverberation in the signal picked up by a single microphone. The method makes extensive use of harmonicity, a unique characteristic of speech, in the design of a dereverberation filter. In particular, harmonicity enhancement is proposed and demonstrated as an effective way of estimating a filter that approximates an inverse filter corresponding to the room impulse response. Two specific harmonicity enhancement techniques are presented and compared; one based on an average transfer function and the other on the minimization of a mean squared error function. Prototype HERB systems are implemented by introducing several techniques to improve the accuracy of dereverberation filter estimation, including time warping analysis. Experimental results show that the proposed methods can achieve high-quality speech dereverberation, when the reverberation time is between 0.1 and 1.0 s, in terms of reverberation energy decay curves and automatic speech recognition accuracy