On improvement of performance of isolated word recognition for degraded speech

We investigate the performance of an isolated word speech recognition (IWSR) system for degraded speech. We propose a recognition scheme which adapts itself to mild degradations in speech and improves the reliability of recognition significantly. The scheme does not use a priori information regarding the nature and extent of noise. We suggest techniques which adaptively discriminate between noisy and noise-free parameters by using a selective weighting procedure in the final distance calculation. A new measure of performance is adopted to compare several recognition schemes using small data sets. Our scheme lends itself to greater flexibility in handling degradations in speech input than do the existing recognition schemes.