Performance of Harpy speech recognition system for speech input with quantization noise

TLDR: The objective of this study is to evaluate the performance of the Harpy continuous speech recognition system when the speech input to the system is corrupted by the quantization noise of an ADPCM system.

Abstract: One of the major problems of a speech processing system is the degradation it suffers due to distortions in the speech input. One such distortion is caused by the quantization noise of waveform encoding schemes which have several attractive features for speech transmission. The objective of this study is to evaluate the performance of the Harpy continuous speech recognition system when the speech input to the system is corrupted by the quantization noise of an ADPCM system. The Harpy system uses segmentation of continuous speech based on Itakura metric and LPC‐based parameters for template generation. The effect of quantization noise on the segmentation and the estimation of LPC‐based parameters is studied for different bit rates in the range 16–48 kbs of the ADPCM system and the overall word and sentence recognition accuracies are evaluated.