Temporal envelope and periodicity components (TEPC) offer robust cues for speech recognition, even spectral information in the speech signal are not readily available. Many previous studies investigated the contribution of TEPC on speech recognition in English, but very few of them investigated the contribution of TEPC on tonal language and particularly on lexical tone recognition. Lexical tones encode lexical and grammatical meanings of words in tonal languages, and are essentially represented by the fundamental frequency and its low-order harmonics. Listeners with cochlear hearing loss have reduced frequency selectivity, causing much broader auditory filters than normal hearing listeners. Spectral cues in the speech signal are much reduced and hearing-impaired listeners have to rely more on TEPC for speech understanding. TEPC extracted from different frequency regions do not necessarily contribute equally for speech recognition. These frequency-specific TEPC contributions vary among different types of speech materials. Such investigation has not been conducted thoroughly for lexical tone yet. / This high frequency TEPC advantage maintained in conditions where the TEPC were carried in noise bands sharing the same frequency region as the frequency region where the TPEC were extracted, or in conditions where TEPC extracted from different frequency regions were carried by fixed high frequency noise bands, even when only a single noise band was used as the carrier. Consistent results were obtained using different lexical tone testing materials. TEPC extracted from the male voice than the female one consistently yielded better performance. Although hearing-impaired listeners performed not as good as their normal hearing peers, they were able to utilize the available TEPC information significantly particularly when TEPC from high frequencies were available. The high frequency TEPC advantage can be explained by the bandwidth of the carrier. Certain critical TEPC modulations for lexical tone recognition are believed to reside only in the high frequency regions but not the low frequency ones. Signal processing methods that can preserve or enhance TEPC in the high frequency regions in the speech signal may improve lexical tone recognition or even overall speech recognition of hearing-impaired listeners. / This research project was aimed at investigating the contribution of TEPC for lexical tone recognition in Cantonese which is a tonal language widely spoken in Chinese communities around the world. By comparing the contributions of TEPC extracted from different frequency regions on lexical tone recognition from a series of experiments, TEPC from high frequency regions always outperformed those from the low frequency regions, based on group analysis on closed-set corrected rationalized arcsine transformed scores, percentage of information transmission, and multidimensional scaling analysis; and on individual subject analysis on binomial distribution of proportion correct scores. / Yuen, Chi Pun. / Source: Dissertation Abstracts International, Volume: 70-09, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 255-262). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_344401 |
| Date | January 2009 |
| Contributors | Yuen, Chi Pun., Chinese University of Hong Kong Graduate School. Division of Surgery. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, theses |
| Format | electronic resource, microform, microfiche, 1 online resource (xiv, 263 leaves : ill.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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