Accession Number:

ADA285932

Title:

A Wavelet Model for Vocalic Speech Coarticulation

Descriptive Note:

Technical rept.

Corporate Author:

PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB

Personal Author(s):

Report Date:

1994-10-01

Pagination or Media Count:

186.0

Abstract:

A known aspect of human speech is that a vowel produced in isolation for example, ee is acoustically different from a production of the same vowel in the company of two consonants deed. This phenomenon natural to the speech of any language, is known as consonant-vowel-consonant coarticulation. The effect of coarticulation results when a speech segment d dynamically influences the articulation of an adjacent segment ee within deed. A recent development in the theory of wavelet signal processing is wavelet system characterization. In wavelet system theory, the wavelet transform is used to describe the time-frequency behavior of a transmission channel, by virtue of its ability to describe the time-frequency content of the systems input and output signals. The present research proposes a wavelet-system model for speech coarticulation wherein, the system is the process of transformation from a control speech state input to an effected speech state output. Specifically, a vowel produced in isolation is transformed into an effected version of the same vowel produced in consonant-vowel-consonant, via the coarticulation channel. Quantitatively, the channel is determined by the wavelet transform of the effected vowels signal, using the control vowels signal as the mother wavelet. A practical experiment is conducted to evaluate the coarticulation channel using samples of real speech. The results show that the model is capable of depicting coarticulation effects associated with certain vowel-consonant combinations. They suggest that elements of the vowels acoustic composition are continuously present, in a modified form throughout the consonant-vowel transition. For other phonetic combinations. however, the model does not respond to instances of segmental transition in a characteristic way.

Subject Categories:

  • Linguistics
  • Anatomy and Physiology
  • Cybernetics
  • Miscellaneous Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE