Sixth European Conference on Speech Communication and Technology

Budapest, Hungary
September 5-9, 1999

Effects of Stress and Lexical Structure on Speech Efficiency

Rob J. J. H. van Son, Louis C. W. Pols

Institute of Phonetic Sciences/IFOTT, University of Amsterdam, The Netherlands

It is proposed that some of the variation in speech is the result of an effort to communicate efficiently. Speaking is considered efficient if the speech sound contains only the information needed to understand it. This efficiency is tested by means of a corpus of spontaneous and matched read speech, and syllable, word, and N-gram frequencies as measures of information content (1582 intervocalic consonants, and 2540 vowels). It is indeed found that the duration and spectral reduction of consonants and vowels from stressed syllables correlate with syllable and word frequencies, as does consonant intelligibility. Correlations for phonemes from unstressed syllables are generally weaker or absent. N-gram models of word predictability did not correlate with any of the factors investigated. Simple N-grams seem to be a poor model for human word prediction. It is concluded that the principle of efficient communication organizes at least some aspects of speech production.

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Bibliographic reference.  Son, Rob J. J. H. van / Pols, Louis C. W. (1999): "Effects of stress and lexical structure on speech efficiency", In EUROSPEECH'99, 439-442.