Coarticulation

Abstract The study of coarticulation—namely, the articulatory modification of a given speech sound arising from coproduction or overlap with neighboring sounds in the speech chain—has attracted the close attention of phonetic researchers for at least the last 60 years. Knowledge about coarticulatory patterns in speech should provide information about the planning mechanisms of consecutive consonants and vowels and the execution of coordinative articulatory structures during the production of those segmental units. Coarticulatory effects involve changes in articulatory displacement over time toward the left (anticipatory) or the right (carryover) of the trigger, and their typology and extent depend on the articulator under investigation (lip, velum, tongue, jaw, larynx) and the articulatory characteristics of the individual consonants and vowels, as well as nonsegmental factors such as speech rate, stress, and language. A challenge for studying coarticulation is that different speakers may use different coarticulatory mechanisms when producing a given phonemic sequence and they also use coarticulatory information differently for phonemic identification in perception. More knowledge about all these research issues should contribute to a deeper understanding of coarticulation deficits in speakers with speech disorders, how the ability to coarticulate develops from childhood to adulthood, and the extent to which the failure to compensate for coarticulatory effects may give rise to sound change.