Gestural overlap and C-center in selected French consonant clusters

Inter-consonantal cohesion in French word-initial CC clusters is investigated in light of recent proposals of gestural coordination. Specifically, the timing of lip and tongue movements of C1/l/ and C1/n/ productions, with C1 being one of the consonants /p, f, k/, of two speakers were studied using electromagnetic articulography (EMA). In French, C/l/ clusters occur frequently in word-initial position, while C/n/ sequences have a limited distribution in less common words. The results provide evidence that liquid as well as nasal sequences consistently show the same ‘place of articulation’ effect of gestural overlap as previously reported for stop-stop clusters, with more overlap in front-to-back than back-to-front sequences. This suggests that the effect is partially due to low-level motor constraints rather than considerations of perceptual recoverability. Furthermore, the results show that the lexical frequency of the sequence does not influence the timing in a simple, categorical manner: stop-nasal clusters showed a strikingly different inter-gestural coordination in comparison with their stop-/l/ counterparts, while no such differences could be observed for the fricative pair. An additional analysis of the overall C-centre of the CC structures demonstrated a rather high temporal stability suggesting that there is, despite many timing differences emerging at the phonetic surface, a relative constant phasing between initial consonant sequence and following vowel.