15th International Congress of Phonetic Sciences (ICPhS-15)
Direct laryngoscopic articulatory evidence from four languages in three unrelated families demonstrates the existence of epiglottal stop in the pharyngeal series. In each language, Nuuchahnulth (Wakashan), Nlaka'pamux (Salish), Arabic (Semitic), and Tigrinya (Semitic), glottal stop also exists in the glottal series as a complement to epiglottal stop, and in three of the languages, a voiceless glottal fricative and a voiceless pharyngeal fricative are also found. In Nlaka'pamux, a pair of voiced pharyngeal approximants (sometimes realized as pharyngealized uvulars) is found instead of the voiceless pharyngeal fricative. As the most extreme stricture in either the glottal or the pharyngeal series, epiglottal stop is a product of full constriction of the aryepiglottic laryngeal sphincter and functions as the physiological mechanism for optimally efficient complete airway occlusion. In this sense, glottal stop represents only slight engagement of the sphincter and functions physiologically as only minimum protective closure, as specified by Gauffin (1977).
Bibliographic reference. Esling, John H. (2003): "Glottal and epiglottal stop in Wakashan, Salish, and Semitic", In ICPhS-15, 1707-1710.