Noise compensation algorithms for use with hidden Markov model based speech recognition

A preliminary theoretical and experimental examination is made of three noise compensation techniques. The three techniques are those due to: Klatt (1976); Bridle et al (1984); and Holmes & Sedgwick (1986). The first two of these techniques have been re-interpreted for use within a hidden Markov model based recogniser. A description is given of how this was done, together with a discussion on some implementation considerations. Experimental results are given for the performance of the algorithms at various signal-to-noise ratios. The principles of recognition in noise are discussed from an implementation point of view and it is shown how the three techniques can be viewed as variations on a single theme