Voice Onset Time Contrasts in Tripolitanian Libyan Arabic Stops

This study aims to investigate the duration of voice onset time of single stop consonants in Tripolitanian Libyan Arabic. It also seeks to identify any potential influence of the place of articulation of these stops and the vocalic context on this duration. Four Tripolitanian Libyan Arabic speakers were recorded while producing 39 monosyllabic words with /b/, /t/, /d/, /k/ and /ɡ/ followed by the vowels /iː/,/i/,/aː/,/a/,/uː/,/u/, /eː/ and /oː/. The duration of positive voice onset time was measured from the release burst to the onset of vocal fold vibration. For negative voice onset time, the duration was measured from the initiation of voicing during the hold phase to the release burst. Results of the analysis show that voice onset time in Tripolitanian Libyan Arabic Falls under two categories. While voiceless stops have a positive voice onset time value ranging from 14 ms to 44 ms, voiced stops have a negative voice onset time ranging from –33 to –60. Results have also revealed that voice onset time varies as a function of the place of articulation of the stop and the quality and duration of the following vowel. As the stop's place of articulation moved from an anterior to a posterior point in the vocal tract, the duration of voice onset time seemed to increase. The duration of voice onset time is longer when voiceless stops are followed by a close vowel, compared to when the stop was followed by a non-high vowel. Finally, voice onset time was longer when voiceless stops were followed by the long vowels /i:/ and /u:/. This tendency was not observed when the stops were followed by /a:/.