Strident vowels (also called sphincteric vowels) are strongly pharyngealized vowels accompanied by an (ary)epiglottal trill, with the larynx being raised and the pharynx constricted. Either the epiglottis or the arytenoid cartilages thus vibrate instead of the vocal cords. That is, the epiglottal trill is the voice source for such sounds.
Strident vowels are fairly common in Khoisan languages, which contrast them with simple pharyngealized vowels. Stridency is used in onomatopoeia in Zulu and Lamba.[page needed] Stridency may be a type of phonation called harsh voice. A similar phonation, without the trill, is called ventricular voice; both have been called pressed voice. Bai, of southern China, has a register system that has allophonic strident and pressed vowels.
There is no official symbol for stridency in the IPA, but a superscript ⟨ʢ⟩ (for a voiced epiglottal trill) is often used. In some literature, a subscript double tilde (≈) is sometimes used, as seen here on the letter ⟨a⟩ (⟨a᷽⟩):
It has been accepted into Unicode, at code point U+1DFD.
These languages use phonemic strident vowels:
- Tuu languages
- Ladefoged, Peter; Maddieson, Ian (1996). The Sounds of the World's Languages. Oxford, UK: Blackwell Publishers. pp. 310–311. ISBN 0-631-19814-8. LCCN 94-49209.
- Miller-Ockhuizen, Amanda (2003). The phonetics and phonology of gutturals: case study from Juǀʼhoansi. Outstanding dissertations in Linguistics. New York City, NY: Routledge. p. 99. doi:10.4324/9780203506400. ISBN 9780415861410. LCCN 2003046887.
- Doke, C. M. (1936). "An outline of ǂKhomani Bushman phonetics". Bantu Studies. 10 (1). doi:10.1080/02561751.1936.9676037.
- Moisik, Scott; Czaykowska-Higgins, Ewa; Esling, John H. (Winter 2012). Loughran, Jenny; McKillen, Alanah (eds.). "The Epilaryngeal Articulator: A New Conceptual Tool for Understanding Lingual-Laryngeal Contrasts". McGill Working Papers in Linguistics. McGill University. 22 (1).