An obstruent (/ˈɒbstruːənt/) 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.[1] All obstruents are consonants, but sonorants include vowels as well as consonants.
Obstruents are subdivided into:
Obstruents are often prototypically voiceless, but voiced obstruents are common. This contrasts with sonorants, which are prototypically voiced and only rarely voiceless.[citation needed]