Gestural overlap and recoverability: Articulatory evidence from Georgian

According to previous investigations of gestural patterning, consonant gestures exhibit less temporal overlap in a syllable/word onset than in a coda or across syllables. Additionally, front-to-back order of place of articulation in stop-stop sequences (labial-coronal, coronal-dorsal, labial-dorsal) exhibits more overlap than the opposite order. One possible account for these differences is that substantial overlap of obstruent gestures may threaten their perceptual recoverability, particularly word/utterance-initially and in a back-to-front sequence. We report here on a magnetometer study of gestural overlap, investigating the role of perceptual recoverability. We focus on Georgian, which allows stop sequences in different positions in the word. C1C2 sequences were examined as a function of position in the word, and the order of place of articulation of C1 and C2. The predictions were borne out: more overlap was allowed in positions where recoverability of C1 is less easily compromised (word-internally and in front-to-back sequences). Similar recoverability requirements are proposed to account for consonant sequencing phenomena violating sonority. Georgian syllable onsets violate sonority, but are apparently sensitive to gestural recoverability requirements as reflected in overlap patterns. We propose that sonority sequencing allows gestures to overlap while still allowing recoverability, but this function can apparently be filled in other ways.