coarticulations

Coarticulation is the overlap of articulatory movements that occurs when producing sequences of sounds. Rather than each sound occupying a completely separate, isolated gesture, the articulators (lips, tongue, jaw) begin preparing for a following sound while the current sound is still being produced. This overlap creates continuous speech and allows for rapid sequencing of phonemes.

There are anticipatory coarticulation effects, where features of an upcoming sound influence the current one, and carryover effects, where features of a preceding sound persist into the next. Articulatory constraints and motor planning lead to gradual, gradient changes in tongue height, lip rounding, and jaw position. For example, the mouth tends to adjust before a rounded vowel or a velar consonant, and the preceding vowel’s formant structure shows transitions that reflect the upcoming consonant.

Acoustically, coarticulation is often visible in formant transitions and in spectral cues that listeners use to identify phonemes. The same patterns can be measured with imaging methods and motion tracking, such as ultrasound, MRI, or X-ray microbeam, which reveal overlapping gestures. Coarticulation plays a key role in speech perception, enabling listeners to integrate segments across boundaries and to predict upcoming sounds.

In linguistics, coarticulation informs theories of phonetics and phonology, and is central to speech synthesis and recognition. It is not a problem to be eliminated; rather, it reflects the efficiency and variability of human speech across languages and speaking styles.