The purpose of this study is to examine voice onset time as a phonetic correlate of voicing distinction in standard Persian. Issues pertinent to VOT are also addressed: namely, the effect of place of articulation, vowel context and sex of speakers. The VOTs were measured from recordings of five male and five female speakers reading 65 words that contained a full set of Persian oral stops in word initial and intervocalic positions. This acoustic experiment indicated that VOT distinguishes voiced from voiceless stops. The results also revealed that Persian uses mainly {voiceless unaspirated} and {voiceless aspirated} categories for [±voice] distinction in initial position and {voiced} and {voiceless aspirated} categories in intervocalic position. Vowel context also affected VOT values but the only significant difference was due to high vowels, which caused the preceding voiceless stop to have a longer VOT. Examining sex differences in the VOT values indicated that for voiced items females produced longer VOTs than males. However, voiceless items displayed no significant sex differences for VOT values. Fundamental frequency (F0) of the onset of the following vowel was also examined as another cue to voice distinction. Although the F0 values of voiceless tokens were higher than those of the voiced ones in each voiced–voiceless category, the results suggest that F0 is not a major cue distinguishing the two stop categories.
Sex differences in voice onset time: A developmental study of phonetic context effects in British English
