INTELLIGIBILITY OF FILTERED SPEECH AND ESTIMATION OF FREQUENCY-IMPORTANCE FUNCTIONS
| Author: |
Kasturi, Kalyan S. |
| Advisor: |
Philip Loizou |
| URL: |
http://www.utdallas.edu/~loizou/thesis/kalyan_ms_thesis.pdf
" target="_blank"> http://www.utdallas.edu/~loizou/thesis/kalyan_ms_thesis.pdf
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| Completion Date: |
August 2002 |
| Degree: |
M.Sc./M.A. |
| Institution: |
University of Texas at Dallas |
| Abstract: |
An understanding of how information about the speech signal is spread among the various frequency bands of the spectrum is essential in numerous communications, audio and hearing related applications. Although many studies investigated the intelligibility of high-pass, low-pass and band-pass filtered speech, not many studies investigated the perception of band-stop filtered speech (i.e., speech with holes in the spectrum) or speech composed of disjoint frequency bands. The most recent studies examined speech recognition either for a single hole varying in frequency location and size or for a single hole in the middle of the spectrum. The scope of these studies is limited in the sense that they did not consider perception of speech composed of multiple disjoint bands involving low, middle and/or high frequency information. The present study addresses this question in a systematic fashion, considering all possible combinations of missing disjoint bands from the spectrum. In this work, we also derive frequency-importance functions for consonant and vowel recognition using (a) a least squares approach that utilizes the results of intelligibility tests for speech with holes in the spectrum and (b) an information theoretic approach based on the calculation of mutual information between frequency bands and phonetic labels. |
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