Title: Processing and feature analysis of stressed speech in speech recognition

Authors: Yonglian Wang, Nazeih M. Botros, Ismail Shahin

Addresses: Department of Electrical and Computer Engineering and Computer Science, Ohio Northern University, Ada, OH 45810, USA. ' Department of Electrical and Computer Engineering, Southern Illinois University at Carbondale, IL 62901-6603, USA. ' Department of Electrical and Computer Engineering, University of Sharjah, Sharjah 27272, UAE

Abstract: In this paper, stressed speech signals are processed, analysed in three feature domains, and then recognised in Hidden Markov Models (HMMs) in Matlab. The Linear Predictive Coding (LPC) cepstral feature analysis is used to obtain the observation vector and the input vector for HMM. Feature analysis explored the characteristics of stress-induced speech compared with normal talking speech. Speech recognition performance degrades greatly owing to the occurrence of stress. A stress compensation technique is utilised to compensate for stress distortion so as to improve speech recognition performance. Four stress styles (neutral, angry, question and Soft) from SUSAS database are used to test recognition performance of speaker-independent isolated word system. Our results show that speech spoken under angry and question stress contains more stress components generating extremely wide fluctuations with average higher pitch, higher intensity and more energy compared with neutral. The recognition rate has increased up to 10% for stressed speech with stress compensation.

Keywords: speech analysis; speech processing; stress compensation; recognition performance; stressed speech signals; speech recognition; hidden Markov models; HMM linear predictive coding; LPC cepstral feature analysis.

DOI: 10.1504/IJFIPM.2009.030832

International Journal of Functional Informatics and Personalised Medicine, 2009 Vol.2 No.4, pp.346 - 357

Published online: 08 Jan 2010 *

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