Productions of English vowels by native speakers of Arabic: acoustic measurements and accentedness ratings.

Productions of ten English vowels in /bVt/ and /bVd/ contexts were elicited from a group of native American English speakers and a group of native Arabic speakers who had learned English in adulthood. When a variety of acoustic measurements, including vowel durations, F1 and F2 frequencies, and movement in F1 and F2 were examined, the two groups were found to differ on at least one of these parameters for nearly every vowel considered. A subset of the Arabic speakers' productions, and the productions of two native English speakers, were rated for accentedness by five native English judges. The rating data indicated that only a minority of the Arabic group's productions were regarded by the judges as "native-like". When the acoustic measurement data were regressed on the mean ratings, it was found that the accentedness scores were correlated primarily with F1 frequency and movement in F2, although the significant predictors varied from vowel to vowel.