Velopharyngeal Closure Force and Levator Veli Palatini Activation Levels in Varying Phonetic Contexts

Abstract

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.

The effect of speaking rate on velopharyngeal function in healthy speakers

“…Similarly, a measure of velar-to-pharyngeal wall contact force during the production of sustained vowels revealed that velar closing force was higher for high (/i/ and /u/) versus low (/ae/ and /α/) vowels (Kuehn & Moon, 1998;Moon, Kuehn, & Huisman, 1994). Velar position differed for consonants as well and was sensitive to place of articulation, voicing, and manner of production (Bell-Berti, 1980;Krakow, 1993;Kuehn & Moon, 1998). For example, Kuehn and Moon (1998) discovered that, in a high-back vowel context, VP closure may be tighter for dorsal /k/ versus apical /t/ in males.…”

“…Obstruent consonants such as /p/ are produced with the velum in an elevated position, allowing for the adequate build up of intraoral pressure. The degree of velar elevation differs for specific sounds (Bell-Berti, 1980) and is also dependent on phonetic context (Kuehn & Moon, 1998), prosodic factors such as position in an utterance and stress (Krakow, 1993), and speaking rate (Bell-Berti & Krakow, 1991a;Bell-Berti, Krakow, Gelfer, & Boyce, 1995;Bzoch, 1968;Kent, Carney, & Severeid, 1974;Kuehn, 1976;Moll & Shriner, 1967). VP function might also be influenced by age and gender (Hoit, Watson, Hixon, McMahon, & Johnson, 1994;Hutchinson, Robinson, & Nerbonne, 1978;McKerns & Bzoch, 1970;Seaver, Dalston, Leeper, & Adams, 1991;Thompson & Hixon, 1979;Zajac & Mayo, 1996;Zajac, 1997).…”

“…Movement studies have shown that velar position for vowels seems to decrease through the series /i/, /u/, /o/, /e/, /a/ (see Bell-Berti, 1980 for a review; Krakow, 1993;Ushijima & Sawashima, 1972). Similarly, a measure of velar-to-pharyngeal wall contact force during the production of sustained vowels revealed that velar closing force was higher for high (/i/ and /u/) versus low (/ae/ and /α/) vowels (Kuehn & Moon, 1998;Moon, Kuehn, & Huisman, 1994). Velar position differed for consonants as well and was sensitive to place of articulation, voicing, and manner of production (Bell-Berti, 1980;Krakow, 1993;Kuehn & Moon, 1998).…”

“…Velar position differed for consonants as well and was sensitive to place of articulation, voicing, and manner of production (Bell-Berti, 1980;Krakow, 1993;Kuehn & Moon, 1998). For example, Kuehn and Moon (1998) discovered that, in a high-back vowel context, VP closure may be tighter for dorsal /k/ versus apical /t/ in males. Males also exhibited less velar closing force for voiced as compared to voiceless alveolar fricatives in a high-vowel context (Kuehn & Moon, 1998).…”

Concordância entre os testes perceptivos e a videofluoroscopia no diagnóstico da disfunção velofaríngea

“…Essa variação da emissão de ar nasal e da hipernasalidade pode acontecer de acordo com a vogal usada na amostra de fala. Alguns autores relatam que a produção de vogais altas requer maior força de fechamento velofaríngeo, quando comparada à produção das demais vogais, dessa forma, é mais suscetível à presença da emissão de ar nasal e da hipernasalidade (KUEHN; MOON, 1998;SEUNGHEE et al, 2004;HENNINGSSON et al, 2008 DALSTON, 1991;HARDIN et al, 1992;DOTEVALL et al, 2002;SWEENEY;SELL, 2008).…”