Simulation and classification of glottal waveforms

S32

93rd Meeting: Acoustical Society of America

S32

nique using high-speed photography of oscillographic traces

cause differences in lip positions compensate for differences

reported by H. Hollien, J. Michel and E.T. Doherty ["A

in tongueshapes. [Work supportedby NSF Grant 75-07158.]

method for analyzing vocal jitter in sustained phonation," J. Phonet. 1, 85--91 (1973)]. Such validation provides evidence that FFI can be utilized as the basis of a rapid and efficient jitter analysis system. 3:48

P10. Simulation and classification of glottal waveforms. I.R. Titze and D.T. Talkin (Sensory Communication Research

Laboratory, Gallaudet College, Washington, DC 20002) Glottal volume velocity and glottal transdonconductance are simulated with a computer model of the vocal folds. The simulated glottal transconductance is shown to be a facsimile of electroglottographic and ultrasonic waveforms recorded by other investigators. The control parameters of the model are cricothyroid contraction, thyroarytenoid contraction, subglottal pressure, and contraction of the primary adductorabductors. A variety of glottal waveforms are generated by different combinations of these control parameters, demonstrating quantitatively the effects of contracting laryngeal

4:24

P13. Sibilant production: three-dimensional reconstruction of normal articulatorv constriction using dental impression material. George D. Allen (University of North Carolina, Chapel Hill, NC 27514) Theoretical models of airway constriction for sibilants make assumptions which may or may not be justified and which are difficult to extend to pathological cases such as realocclusion. In an attempt to determine the exact shape of the constriction, fast-setting dental impression m•,terial was placed in the mouths of normal English speaking adults, who then attained

and held articulatory positionsfor/s/

and/•e/. The impres-

sions thus formed

to obtain

were

then

links

between

neuromuscular

control

signal. [Supportedby NIH Grant No. I R01 DE04267. ]

phonation bear this out. 4:OO

Pll. Estimation of laryngeal control parameters from glottal waveforms. D.T. Talkin and I.R. Titze (Sensory Communication Research Laboratory, Gallaudet College, Washington, DC 20002)

Clinical assessment'of phonatory skills and laryngeal abnormalities would be facilitated if a method of relating laryngeal muscular control and glottal configuration to glottal waveforms could be found. A computer model of the vocal folds, described earlier, which uses control parameters closely related to laryngeal muscular contractions, and which allows for sufficient flexibility in tissue properties and configuration, has been used to generate prototype waveforms of glottal transconductance and glottal volume velocity. The relationship between model control parameters and the resultant waveforms is determined by multiple regression. Success in predicting model control parameters from waveform parameters is demonstrated, and the applicability of this method to clinical situations

4:36

and acoustic

output are laryngeal configuration and viscoelastic tissue properties. Qualitative (perceptual) effects of simulated

is discussed. 4:12

P12. Formant frequencies corresponding to different vocal tract shapes. Peter Ladefoged and Lloyd Rice (Phonetics Laboratory, Linguistics Department, UCLA, Los Angeles, CA 90024)

A computer model was used to generate the formant frequencies corresponding to different vocal tract shapes. The degree of lip opening was varied exponentially in five steps. The tongue position was varied in equal steps in accordance with the two factors previously found to underlie English vowels. Sets of approximately 1500 different vocal tract shapes were generated, the exact number in each set depending on how the limits of possible vowels are determined. The formants of these Sets of vowels are not evenly distributed throughout the formant space. A high proportion of them are in the area of the front vowels from Ill to [•e]. In most cases formant fre-

quencies that differ by small amounts are associated with vocal tract shapes that also differ by small amounts. But there are also cases in which a set of formant frequencies can be produced with very different vocal tract shapes, usually be-

successive

cross-sectional areas. There is wide variability among norreal speakers in the observed cross-sectional area patterns, and an attempt will be made to relate these differences to variations in air flow and pressure and the resulting acoustic

muscleson voice production. Wg note that the primary mechanical

sectioned

P14. Acoustic reasons why labio-velars are both labials and velars. John J. Ohala and James Loreritz (Phonology Labora-

tory, Department of Linguistics, University of California, Berkeley, CA 94720) The phonological literature

reveals an interesting asym-

merry in the behavior of labio-velar speech sounds, i.e., w, u, kp, gb, etc., namely, that when nasalized or determining the place of articulation via assimilation of adjacent nasal consonants, they behave primarily like velars not labials, whereas when they become fricativized or determine the place of articulation of adjacent fricatives, they behave primarily like labials, not velars. The reasons for this will be explained by reference to well-known principles of acoustic phonetics. It will be shown that for nasals the most important of multiple oral constrictions case of fricatives

is the rear-most constriction whereas in the it is the front-most constriction which is

most important in determining the characteristics of the output sound. This case is offered as another example of the ap-

plication of physics to philology. [Supportedby National Science Foundation.

] 4:48

P15. Vertical larynx position in whispered speech. Carol Riordan (Phonology Laboratory, University of California, Berkeley, CA and Speech Research Laboratory, Veterans Administration Hospital, San Francisco, CA) A number of studies have shown that vertical larynx position varies depending on the vowel or consonant uttered. Voiceless stops, for example, are generally produced with a higher larynx than their voiced cognates. It is not clear, however, whether the larynx is perturbed upward for voiceless stops or downward for the voiced stops. The latter possibility is suggested by the increase in pharyngeal cavity size for voiced stop articulation, presumably to maintain the transgottal flow

necessary for voicing [Bell-Berti, 1975], and by the similarity in larynx height data for sonorants and voiceless stops [Ewan, 1976]. The present experiment is designedto determine the effect on larynx height of sounds with aerodynamic requirements different from those of stops. Vertical larynx position is monitored photoelectrically while English speakers produce

intervocalic/t, d, n, l, r, f, v, s, z/first under normal speech conditions and then in whisper. Implications of these results are discussed. [Supportedby NSF and the Veterans Medical Service. ]

J. Acoust. Soc. Am., Vol. 61, Suppl. No. 1, Spring 1977

Redistribution subject to ASA license or copyright; see http://acousticalsociety.org/content/terms. Download to IP: 191.96.248.49 On: Thu, 08 Dec 2016 05:15:24