Social factors condition consonant separation in Moroccan Arabic word-initial clusters: Amazigh-Arabic bilingualism, region, and speaking style

Moroccan Arabic is a regional variety of spoken Arabic that contains linguistic features, which make it distinct from other dialects. Moroccan Arabic, for instance, contains a larger number of words with consonant clusters, a result of a historical vowel reduction process, compared to other Eastern varieties. Even within Moroccan Arabic, there is variation across speakers that is relatively understudied. The present study investigates across- and within-speaker factors that condition variation in the duration of acoustic separation between adjacent consonants in word-initial clusters in Moroccan Arabic. Three factors are examined: speaking style (clear vs fast speech), speaker region of origin (the Easternmost region of Morocco vs other regions), and speaker first language (Moroccan Arabic vs an Amazigh language). It is determined that (1) speakers produce more frequent, and longer when present, consonant separation in clear speech; (2) Amazigh-Arabic bilingual speakers produce higher rates and longer durations of consonant separations between adjacent consonants; and (3) regional dialect variation is also observed: speakers of Easternmost Moroccan Arabic produce more frequent and longer consonant separations than speakers from other Moroccan regions. Results are discussed for implications of speech production models as well as for theories of sound change.