The purpose of this study was to measure velopharyngeal closure force in varying phonetic contexts for normal men and women subjects. Levator veli palatini muscle activity was measured as well. Place and manner of articulation, voicing, and the effects of consonant sequencing were studied in different vowel contexts. When the data were grouped by sex of subject, no differences were found in absolute values of velopharyngeal closure force for the men versus women subjects. As expected, nonnasal consonants were produced with greater velopharyngeal closure force than nasal consonants. High vowels were produced with greater closure force than low vowels. Closure force was greater for voiceless than for voiced consonants but only for the men and only within /i/ and /u/ contexts. The lingua-dorsal consonant was associated with greater closure force than the lingua-apical consonant but only for the men and only in the high-back vowel environment. Significant differences in closure force were not found between fricatives or stops. A tendency for greater closure force for the fricative consonant was observed when the fricative followed rather than preceded the nasal consonant. Vowel identity had an effect on closure force during consonant production in the men in that closure force was greater for /s/ and /n/ in high versus low vowel contexts. Men exhibited a larger number of significant differences in closure force than did the women. The results suggest that velopharyngeal closure force is not controlled by a single muscle (the levator veli palatini) but that other muscles and mechanical factors are likely contributors.

Five laryngectomized, tracheoesophageal (TE) speakers completed a series of phonatory tasks developed to assess (a) aerodynamic and acoustic properties of TE voice and (b) aerodynamic and myoelastic contributions to the mediation of fundamental frequency change. These TE speakers' voices were characterized by increased trans-source airflow rates, comparable source driving pressures, and decreased airway resistances in comparison with standard esophageal speakers. TE speakers were capable of adjusting their voicing sources on a myoelastic basis to influence F o change. This result, coupled with findings that confirm aerodynamic contributions to TE phonation, are intepreted to suggest that TE voice production should be regarded as an aerodynamic-myeolastic event. Findings are integrated with existing data to highlight fundamental differences among TE, esophageal, and normal voice production.

The anatomy of the soft palate from the posterior border of the hard palate to the levator veli palatini sling is consistent among specimens, suggesting that structures in this region have a uniform function across subjects. The paired versus unpaired nature of musculus uvulae is variable both within and between specimens. The posterior one third of the soft palate is variable across specimens with regard to the relative amount and distribution of different tissue types.

This study examined temporal parameters of speech in subjects with apraxia of speech, conduction aphasia, and normal speech. They were asked to repeat target words in a carrier phrase 10 times. Acoustic analyses involved measurement of stop gap duration, voice onset time, vowel nucleus duration, and consonant-vowel (CV) duration. Speakers with apraxia of speech had longer and more variable stop gap, vowel, and CV durations than did subjects with aphasia or normal speech. Speakers with conduction aphasia had longer vowel durations and CV durations than subjects with normal speech. Also, subjects with apraxia of speech showed greater token-to-token variability than the other subject groups. The variability shown by subjects with apraxia of speech was significantly correlated with perceptual judgments of their speech. The significance of these results is discussed in the context of motoric and phonological explanations for apraxia of speech and conduction aphasia.

Objective The purpose of this study was to better understand the muscular anatomy of the ventricular folds (VF) to help improve biomechanical modeling of phonation and to better understand the role of these muscles during phonatory and non-phonatory tasks. Method Four human larynges were decalcified and sectioned coronally from the posterior to anterior using a CryoJane tape transfer system, and stained using Massons trichrome. The total and relative area of muscles observed in each section were calculated and used for characterizing muscle distribution within the ventricular folds. Results The ventricular folds of the larynges contained anteriorly coursing thyroarytenoid and ventricularis muscle fibers lying in the lower half of the VF posteriorly, with some ventricularis muscle evident in the upper and lateral portion of the fold more anteriorly. Very little muscle tissue was observed in the medial half of the fold, and the anterior half of the VF was largely devoid of any muscle tissue. All four VF’s contained muscle bundles coursing superiorly and medially through the upper half of the fold toward the lateral margin of the epiglottis. Conclusions While variability in expression was evident, the well-defined thyroarytenoid muscle was readily apparent lateral to the arytenoid cartilage in all specimens.