Multiresolution channel normalization for ASR in reverberant environments
Carlos Avendaño, Sangita Tibrewala, Hynek Heřmanský · 1997
To overcome the problems related with the long impulse responses produced by reverberation, we use a long time window (high frequency resolution) analysis during the channel normalization steps of the feature extraction process in automatic speech recognition (ASR). After normalization, a trade between frequency and time resolution is used to increase the rate at which the time information is sampled (short-time domain), yielding an appropriate domain to derive ASR features. Experiments on data with reverberation times of about 0:5 s show that the new technique achieves significant performance improvement of a speech recognizer under reverberation, with only some performance degradation on clean speech. 1. INTRODUCTION In spite of the efforts by many researches during the last 50 years, there has been very little success in reducing the effects of reverberation in speech communications. The effects of reverberation on the details of the speech signal are complicated and difficult to ...