Electromyographic-Cinéfluorographic Investigation of Velar Function during Speech Production

Abstract

Cinéfluorographic films of velar movement were made simultaneously with surface electromyographic recordings of velar muscle contraction during the production of selected syllables and sustained vowel and nasal phonemes. The data were analyzed to determine (1) the extent of variation in velar position during the production of various phonemes in relation to alterations in duration and phonetic context; (2) the extent of variation in velar electromyographic activity during the same speech utterances; and (3) the extent to which velar elevation and electromyographic activity covary during the production of sustained vowel and nasal phonemes and during alterations in duration and phonetic context. These data are discussed in relation to the hypothesis, advanced by certain investigators, that the velum acts in an all-or-none (ON-OFF) fashion.

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).…”

Nasal Spreading as Defective Gestural Deactivation

“…Articulatory data supports this theory. Numerous studies including Lubker (1968), Bell-Berti & Hirose (1975), and BellBerti (1976) report raising of the velum during the production of oral stops relative to the height achieved during production of other oral segments.…”

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

“…Several articulatory studies employing different observation techniques have documented the existence of a contextual effect of the nasal sound on the adjacent vowels (e.g., Moll, 1962;Lubker, 1968;Ushijima & Swashima, 1972;Kent, Carney & Severeid, 1974). These studies detected a lower position of the velum during the production of a vowel before and after nasal consonants than for vowels near non-nasal consonants.…”

“…First is the variation in the strength of the levator veli palatine contractions, the primary muscle of velar elevation, which exerts an upward and posterior pull on the velum as documented in electromyography of the levator veli palatine potentials (Moll & Shriner. 1967;Lubker, 1968;Fritzell, 1969;BellBerti, 1973BellBerti, , 1976. The second muscle is the palatoglossus which pulls the velum downward to narrow the faucial isthmus (Bell-Berti, 1973 and resist being stretched during the articulation of low vowels (Moll & Shriner, 1967).…”

“…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).…”