Obstruent (pronounced /ˈɒb.stru.ənt/, OB-stroo-ənt) is a term in phonetics and phonology referring to a class of speech sounds produced by obstructing the airflow in the vocal tract. Obstruents contrast with sonorants, which are produced with a relatively open vocal tract and allow the airflow to resonate freely. All obstruents are consonants, whereas sonorants include both vowels and certain consonants.
Subclasses
Obstruents are divided into three main categories:
- Plosives (oral stops): Sounds produced with complete occlusion of the vocal tract, often followed by a release burst. Examples include [p], [b], [t], [d], [k], and [ɡ].
- Fricatives: Sounds produced with a narrow constriction that creates turbulent airflow but does not stop it entirely. Examples include [f], [v], [s], [z], [ʃ], and [ʒ].
- Affricates: Sounds that begin with a complete occlusion (like a plosive) but release into a fricative-like constriction. Examples include [t͡s], [d͡z], [t͡ʃ], and [d͡ʒ].
Voicing
Obstruents are often prototypically voiceless, but voiced obstruents (such as [b], [d], [ɡ], [v], [z]) are common across languages. This contrasts with sonorants, which are prototypically voiced and only rarely appear as phonemically voiceless sounds.
Phonetic Characteristics
The defining feature of obstruents is the presence of noise (turbulence or a burst of pressure) in their acoustic signal, resulting from the obstruction of airflow. This makes them distinct from sonorants, which have a periodic, resonant quality.
References
- Gussenhoven, Carlos; Haike, Jacobs. Understanding Phonology, Fourth Edition, Routledge, 2017.
- Zsiga, Elizabeth. The Sounds of Language: An Introduction to Phonetics and Phonology. Wiley-Blackwell, 2013.
- Ladefoged, Peter; Maddieson, Ian (1996). The Sounds of the World's Languages. Oxford: Blackwell. ISBN 0-631-19815-6.
- Ian Maddieson (1984). Patterns of Sounds. Cambridge University Press. ISBN 0-521-26536-3.
