Abstract:
One of the main objectives of front-end processing in robust automatic speech recognition (ASR) is to preserve critical linguistic information while suppressing irrelevant information such as speaker-specific characteristics, channel characteristics, and noise. Since the information suppressed in the front end of the recognizer is lost for the recognition process, it is important to identify those features of the signal that are critical for human speech communication. This work examines effects of temporal filtering of the time trajectories of LPC cepstrum. Results of the perceptual experiments show that intelligibility of Japanese syllables is not severely impaired as long as remaining spectral envelope components have a rate of change between about 1 and 20 Hz. Analysis of results for each phoneme class is also reported. [Work supported by DoD under MDA-904-94-C-6169.]