Realisation of Voice Onset Time (VOT) and Its Implication on Voicing of English (RP) Stops in Ghanaian English (GhE)

摘要

There has been a general perception that the English voiced stops /b, d, g/ before and after a pause or silence are more often confused with the initial voiceless stops /p, t, k/. Thus, in distinguishing the two, listeners most often depend on the onset of voicing of the following segments. Voice onset time, therefore, serves as a significant cue in distinguishing English voiced stops from their voiceless counterparts. Interestingly, voiceless stops in many Ghanaian indigenous languages appear to be weakly aspirated; they are perceived to be made with a very short voice onset time. However, listeners are able to distinguish the voiceless stops from their voiced counterparts. What this study sought to do was to investigate the production of English initial voiceless stops, /p, t, k/ in Ghanaian English. Specifically, it sought to examine the voice onset time of the stops, and whether listeners are able to distinguish English stops made with weak aspiration from the voiced stops before and after a pause. The study used 112 Ghanaian speakers, 76 for a production test; they produced 21 tokens of the stops in a /p/-, /t/- and /k/- initial words, and 36 for a perception test; they listened to words produced with voiced stops in a /b-b/, /d-d/ and /g-g/ environments. The study has revealed that for all the voiceless stops, voicing for the following segments began after the stops were released, and there was no pre-voicing or voice lead. However, for some of the stops, voicing coincided with the release, while for some voicing began after an appreciable amount of time after the release burst. The length of the VOT was found to have been affected by place of articulation and vowel contexts. However, speaker sex seems to have no effect on the length of the VOT. It is clear that Ghanaian speakers of English would have no difficulty distinguishing weakly aspirated stops from voiced stops before and after a pause. Also, understanding words having the initial voiced stops before and after a pause and weakly aspirated stops produced by Ghanaians will not be a problem to listeners.