Mathematical model of acoustic speech production with mobile walls of the vocal tract

2016 ◽  
Vol 62 (2) ◽  
pp. 225-234
Author(s):  
N. A. Lyubimov ◽  
E. V. Zakharov
1988 ◽  
Vol 53 (3) ◽  
pp. 232-238 ◽  
Author(s):  
Samuel G. Fletcher

Changes in the dimensions and patterns of articulation used by three speakers to compensate for different amounts of tongue tissue excised during partial glossectomy were investigated. Place of articulation was shifted to parts of the vocal tract congruent with the speakers' surgically altered lingual morphology. Certain metrical properties of the articulatory gestures, such as width of the sibilant groove, were maintained. Intelligibility data indicated that perceptually acceptable substitute sounds could be produced by such transposed gestures.


2003 ◽  
Vol 46 (3) ◽  
pp. 689-701 ◽  
Author(s):  
Steve An Xue ◽  
Grace Jianping Hao

This investigation used a derivation of acoustic reflection (AR) technology to make cross-sectional measurements of changes due to aging in the oral and pharyngeal lumina of male and female speakers. The purpose of the study was to establish preliminary normative data for such changes and to obtain acoustic measurements of changes due to aging in the formant frequencies of selected spoken vowels and their long-term average spectra (LTAS) analysis. Thirty- eight young men and women and 38 elderly men and women were involved in the study. The oral and pharyngeal lumina of the participants were measured with AR technology, and their formant frequencies were analyzed using the Kay Elemetrics Computerized Speech Lab. The findings have delineated specific and similar patterns of aging changes in human vocal tract configurations in speakers of both genders. Namely, the oral cavity length and volume of elderly speakers increased significantly compared to their young cohorts. The total vocal tract volume of elderly speakers also showed a significant increment, whereas the total vocal tract length of elderly speakers did not differ significantly from their young cohorts. Elderly speakers of both genders also showed similar patterns of acoustic changes of speech production, that is, consistent lowering of formant frequencies (especially F1) across selected vowel productions. Although new research models are still needed to succinctly account for the speech acoustic changes of the elderly, especially for their specific patterns of human vocal tract dimensional changes, this study has innovatively applied the noninvasive and cost-effective AR technology to monitor age-related human oral and pharyngeal lumina changes that have direct consequences for speech production.


2013 ◽  
Vol 43 (3) ◽  
pp. 321-337 ◽  
Author(s):  
Susanne Fuchs ◽  
Blake Rodgers

Phonemic clicks are geographically limited to the African continent, but non-phonemic clicks can also occur in languages spoken elsewhere. One of the phonetic peculiarities of clicks is that they involve negative intraoral pressure. The current study is a survey of instances of negative intraoral pressure excursions in German, a European language which is known to show instances of weak clicks in consonant sequences. Data of spontaneous speech in monologues and read passages from 14 female subjects are analysed. Our data provide evidence that negative pressure occurs frequently in speech production, in particular in pauses (between speech intervals), and in consonant sequences. Of particular interest is that clicks can also occur without an obvious dual closure in the vocal tract. Negative pressure in pauses occurs frequently with clicks (but not exclusively) which are aligned with the pressure minimum. We conclude that these aligned clicks are epiphenomenal and reflect the interaction of the respiratory and the laryngeal systems. In consonant sequences, clicks may be present more often with front–back consonant order than the reverse, but in both cases negative pressure can be found.


Phonology ◽  
1998 ◽  
Vol 15 (2) ◽  
pp. 143-188 ◽  
Author(s):  
Grzegorz Dogil ◽  
Jörg Mayer

The present study proposes a new interpretation of the underlying distortion in APRAXIA OF SPEECH. Apraxia of speech, in its pure form, is the only neurolinguistic syndrome for which it can be argued that phonological structure is selectively distorted.Apraxia of speech is a nosological entity in its own right which co-occurs with aphasia only occasionally. This…conviction rests on detailed descriptions of patients who have a severe and lasting disorder of speech production in the absence of any significant impairment of speech comprehension, reading or writing as well as of any significant paralysis or weakness of the speech musculature.(Lebrun 1990: 380)Based on the experimental investigation of poorly coarticulated speech of patients from two divergent languages (German and Xhosa) it is argued that apraxia of speech has to be seen as a defective implementation of phonological representations at the phonology–phonetics interface. We contend that phonological structure exhibits neither a homogeneously auditory pattern nor a motor pattern, but a complex encoding of sequences of speech sounds. Specifically, it is maintained that speech is encoded in the brain as a sequence of distinctive feature configurations. These configurations are specified with differing degrees of detail depending on the role the speech segments they underlie play in the phonological structure of a language. The transfer between phonological and phonetic representation encodes speech sounds as a sequence of vocal tract configurations. Like the distinctive feature representation, these configurations may be more or less specified. We argue that the severe and lasting disorders in speech production observed in apraxia of speech are caused by the distortion of this transfer between phonological and phonetic representation. The characteristic production deficits of apraxic patients are explained in terms of overspecification of phonetic representations.


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