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.
[1] All obstruents are consonants, but sonorants include vowels as well as consonants.
This contrasts with sonorants, which are prototypically voiced and only rarely phonemically voiceless.
This phonetics article is a stub.