Syllable Position Effects on the Coordination of Two Lingual Stop Clusters in Tripolitanian Libyan Arabic: Testing the C-centre Hypothesis

This study aims to test the validity of the C-centre hypothesis by investigating the pattern of temporal organisation of the articulatory gestures of two lingual stop clusters in Tripolitanian Libyan Arabic. Five speakers of Tripolitanian Libyan Arabic produced four singleton stops /t/, /d/, /tˤ/ and /ɡ/, and three back-to-front clusters /ɡt/, /ɡd/ and /ɡtˤ/ in syllable onset and coda positions. The C-center lag for these singletons and the two-stop clusters was measured. The results show that word-initial two-stop consonants in Tripolitanian Libyan Arabic exhibit more inter-consonantal cohesion and overlap than the same clusters in word-final position. While word-initial clusters sometimes allow intrusive vowels, the same clusters in word-final positions have epenthetic vowels. This study proposes that Tripolitanian Libyan Arabic has two coordination patterns governing articulatory gestures of two-stop consonant clusters. First, there is the onset pattern in which the articulatory gestures of the two lingual stops are aligned in close transition, such that the release of the first stop is sometimes masked. In coda position, the articulatory gestures of the two lingual stops are loosely aligned. They exhibit a more open transition and no overlap. The pattern here is characterised by allowing the separation of the two articulatory gestures, leading to the insertion of an epenthetic vowel.