In this paper the design of 'robust' speech recognizers are discussed. Basic principles of noise reduction in connection with speech recognizers are presented. For the noise reduction a one-channel system with spectral subtraction, a two-channel system with adaptive filtering and a four-channel system with adaptive filtering were used. Each of the algorithms are optimized for different SNR's and application cases. The paper describes the noise reduction systems, their integration into the recognizer, different strategies to optimize the filter parameters of the noise reduction filter and it summarizes some preliminary recognition results. Keywords: Speech Recognition, Speech Enhancement, Noise Compensation, Spectral Subtraction
Bibliographic reference. Fellbaum, Klaus / Becker, Dieter (1991): "Isolated word recognition with integrated noise reduction", In EUROSPEECH-1991, 87-90.