What term is used for the articulation that occurs in the same vocal tract area?

The term that describes articulation occurring in the same vocal tract area is known as homorganic articulation. This refers to sounds that share the same place of articulation, meaning that the articulators (such as the tongue, lips, or palate) involved in producing those sounds are in a similar physical configuration within the vocal tract.

Understanding homorganic articulation is important because it helps in recognizing how sounds can influence each other when spoken in sequence, sometimes leading to assimilation where a sound may change due to the influence of a neighboring sound with the same articulatory features. For example, the sounds /b/ and /m/ are homorganic because they are both produced with the lips.

The other terms provided do not accurately represent the concept of sharing the same articulation area. Phonemic articulation pertains to the way sounds function within a particular language's sound system rather than their physical articulation sites. Vocalic articulation refers specifically to vowel sounds and does not encapsulate the broader concept of articulatory characteristics across both vowels and consonants. Contrasting articulation speaks to sounds that are produced differently and may have different meanings, which is contrary to the idea of shared articulation.