The glottal stop between segmental and suprasegmental processing: The case of Maltese

Abstract

Many languages mark vowel-initial words with a glottal stop. We show that this occurs in Maltese, even though the glottal stop also occurs as a phoneme in Maltese. As a consequence, words with and without an underlying (phonemic) glottal stop (e.g., a glottal stop-zero minimal pair qal /?a:l/ vs. ghal /a:l/ Engl., 'he said'-'because') can become homophonous in connected speech. We first tested the extent of this phonetic marking of vowel-initial words in a production experiment and found that even in fluent productions, about half of the vowel-initial words are marked with an epenthetic glottal stop. The epenthetic glottal stop is more likely to occur when the preceding word is longer, showing a kind of preboundary lengthening at a phrase-level prosodic boundary. A subsequent perception study (Experiment 2) using a two-alternative forced-choice task with a minimal pair of a glottal stop-initial and a vowel-initial word indicated that listeners are sensitive to the durationally conditioned prosodic context before the test word, and they are more likely to perceive a vowel-initial word when the preceding word is lengthened. An additional eye-tracking study (Experiment 3) using onset-overlap pairs (e.g., qafla /?afla/ - afda, /afda/ -> [?afda], Engl., 'to trust' - 'chord') showed no early influence of prosodic cues on segmental processing. But a gating experiment (Experiment 4) replicated the prosodic effect observed in Experiment 2. Taken together, our results indicate an interaction between prosodic processing and segmental processing that comes into effect relatively late in speech processing.