A study of ambient and amplitude correction in isolated utterance recognition
Subrata Kumar Das · The Journal of the Acoustical Society of America · 1985
Experiments demonstrating the importance of ambient and amplitude correction in an isolated word speech recognition system are reported. Whenever a speaker produces the speech input in a nonanechoic environment, such as in in ordinary office, the method of ambient correction helps to neutralize the effect of any change in ambient which would otherwise adversely influence the performance of the recognizer. On the other hand, the goal of amplitude correction is to compensate for amplitude level fluctuations encountered in any normal speech input. The experiments compare the performances with and without the corrections in the context of an experimental speech recognition system developed at IBM. A database consisting of the speech collected from three male and one female speaker is used for this study. Performance is measured by examining both the error rate and the time taken by the decoder. Significant improvement in performance is observed on both counts when the corrections are applied.