Cohn's research focuses primarily on phonetics and phonology and their interaction. Often, phonetics and phonology are viewed as distinct areas of study. Yet there is an implicit relationship between phonology --the abstract patterning of sounds as part of a sound system, and phonetics-- the physical output. The nature of this mapping has been at the center of her current research, in which she has investigated both processes and representations within phonology and phonetics. Cohn is also interested in the interaction of phonology and morphology, which interact formally in quite different ways from phonology and phonetics. With respect to language area, she has a particular interest in Indonesian languages and French.