A labial-alveolar consonant is a consonant produced with two simultaneous places of articulation: At the lips ('labial'; a p, b, or m sound), and at the gums ('alveolar'; a t, d, or n sound).
The Yélî Dnye language of Rossel Island, Papua New Guinea, appears to be unique in having distinct labial-alveolar and labial-postalveolar places of articulation, as illustrated below. The alveolars are fronted, and the post-alveolars only slightly retracted, so it may be best not to consider the latter to be retroflex.
In a few African languages, such as Dagbani and Nzema, labial-alveolars are allophones of labial-velars. Something similar is found with the labialized alveolar stops in several Northwest and Northeast Caucasian languages such as Abkhaz and Lak. Although the double stop articulation may be more common, they are generally considered to be essentially labialized alveolars because the labial contact is light, and moreover the contact is between the inner surfaces of the lips, which are protruded as they are for [w]. This is quite different from the normal contact for [p] in these languages. The labial contact may also be realized as a trill. Compare the following minimal sets in Ubykh:
