An obstruent (/ˈɒbstruənt/ OB-stroo-ənt) is a speech sound such as [k], [d͡ʒ], or [f] that is formed by obstructing airflow. Obstruents contrast with sonorants, which have no such obstruction and so resonate. All obstruents are consonants, but sonorants include vowels as well as consonants.
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Obstruent consonant in the context of Sonorant consonant
In phonetics and phonology, a sonorant or resonant is a speech sound that is produced with continuous, non-turbulent airflow in the vocal tract; these are the manners of articulation that are most often voiced in the world's languages. Vowels are sonorants, as are semivowels like [j] and [w], nasal consonants like [m] and [n], and liquid consonants like [l] and [r]. This set of sounds contrasts with the obstruents (stops, affricates and fricatives).
For some authors, only the term resonant is used with this broader meaning, while sonorant is restricted to the consonantal subset—that is, nasals and liquids only, not vocoids (vowels and semivowels).
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