Multi-Microphone Noise Reduction Techniques for Hands-Free Speech Recognition - A Comparative Study

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Abstract:

In this paper we will describe different multi-microphone noise reduction techniques as for example front-end systems for a command speaker-independent word recognizer in an ofﬁce environment. Our focus lies on examining the recognition rate if the noise source is not gaussian and stationary, but a second speaker in the same room. In this case standard noise reduction techniques like spectral subtraction will fail, and only multi-microphone techniques can raise the recognition rate by using the spatial information of the speakers. We will compare the delay-and-sum-beamformer, different superdirective solutions and the post-ﬁlter approach. Our results show that these techniques are the right choice for hands–free speech recognition systems. Furthermore, we will give a deeper insight into the superdirective design for microphone arrays.

Document type:

Conference Paper

Publication:

Tampere, Finland, 25. - 26. May 1999

Conference:

Robust Methods for Speech Recognition in Adverse Conditions (ROBUST 99)

Pages:

171-174

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