An Electromyographic Study of Velopharyngeal Function in Speech

Abstract

Electromyographic (EMG) recordings were obtained from the levator palatini, superior pharyngeal constrictor, middle pharyngeal constrictor, palatoglossus, and palatopharyngeus muscles of three talkers of American English. Bipolar hooked-wire electrodes were used. Each subject read nonsense words composed of three vowels (/i, a, u/), six stop consonants (/p, b, t, d, k, g/), and two nasal consonants (/m, n/) to form various stop-nasal and nasal-stop contrasts. Multiple repetitions of each utterance type were recorded and subsequently processed by computer. The levator palatini was found to be the primary muscle of velopharyngeal closure for each of the subjects. The palatopharyngeus also showed consistent oralization activity for each of the subjects, although the activity of this muscle was strongly affected by vowel environment. Two subjects showed pharyngeal constrictor muscle activity related to oral articulation, but pharyngeal constrictor activity for the third subject was related to vowel quality. Nasal articulation was accomplished by suppression of oral articulation for each subject. Vowel quality affected the strength of EMG signals for lateral and posterior pharyngeal wall muscles. In those cases where activity was different for the three vowels, activity was greatest for /a/.

A Gestural Account of Neutral Segment Asymmetries in Harmony

“…This tight seal prevents nasal leakage and creates the aerodynamic conditions necessary for obstruency. The inclusion of a velum closure gesture for obstruents is supported by experimental results that show raising of the velum during the production of oral stops, even when surrounded by oral vowels (Lubker 1968;Bell-Berti & Hirose 1975;Bell-Berti 1976).…”

The effect of speaking rate on velopharyngeal function in healthy speakers

“…The primary muscle responsible for elevating the velum is the levator veli palatini (Bell-Berti, 1976;BellBerti, 1993) which is innervated by the mandibular branch of the trigeminal nerve (cranial nerve V) (Seikel, King, & Drumright, 1997). The tensor veli palatini, musculus uvulae, palatoglossus, and palatopharyngeus muscles also play a role in changing the shape and position of the velum (Seikel et al, 1997).…”

Temporal and Aerodynamic Aspects of Velopharyngeal Coarticulation: Effects of Age, Gender and Vowel Height

“…Specifically, vowels produced with high tongue position are accompanied with a higher velum and greater VP closure force than vowels produced with lower tongue position (Bell-Berti, 1976;Bell-Berti & Krakow, 1991;Moon, Kuehn & Huisman, 1994;Kuehn & Moon, 1998). In a cineflorographic study, Moll (1962) investigated the variation of VP closure as a function of the vowel produced as well as the consonant environment of the vowel in 10 normal adult speakers during their production of CVC syllables containing the vowels /i/, /ae/, /a/ and /u/.…”

“…The relationship between tongue height and velum height is one of the most documented phonetic factors influencing VP function (Moll, 1962;Moll & Shriner, 1967;Lubker, 1968;Fritzell, 1969;Ohala, 1971;Bell-Berti, 1976;Clumeck, 1976;Bell-Berti, Baer, Harris & Niimi, 1979;Al-Bamerni, 1983;Henderson, 1984;Bell-Berti & Krakow, 1991;Kuehn & Moon, 1998). Bell-Berti (1993) reported that the velum position varies systematically as a function of the phonetic contexts; she explains that "velic position is lowest for nasal consonant, somewhat higher for low vowels, higher still for high vowels, and highest for obstruent consonant" (p.69).…”

“…In oral contexts, high vowels are produced with higher velum position and greater VP closure force than are low vowels (Bell-Berti, 1976;Kuehn & Moon, 1998). In nasal contexts, high vowels are produced with a higher velum position and less VP opening than low vowels (Moll, 1962;Clumeck, 1976;AlBamerni, 1983).…”