Locus equations and coarticulation in three Australian languages.

Locus equations were applied to F2 data for bilabial, alveolar, retroflex, palatal, and velar plosives in three Australian languages. In addition, F2 variance at the vowel-consonant boundary, and, by extension, consonantal coarticulatory sensitivity, was measured. The locus equation slopes revealed that there were place-dependent differences in the magnitude of vowel-to-consonant coarticulation. As in previous studies, the non-coronal (bilabial and velar) consonants tended to be associated with the highest slopes, palatal consonants tended to be associated with the lowest slopes, and alveolar and retroflex slopes tended to be low to intermediate. Similarly, F2 variance measurements indicated that non-coronals displayed greater coarticulatory sensitivity to adjacent vowels than did coronals. Thus, both the magnitude of vowel-to-consonant coarticulation and the magnitude of consonantal coarticulatory sensitivity were seen to vary inversely with the magnitude of consonantal articulatory constraint. The findings indicated that, unlike results reported previously for European languages such as English, anticipatory vowel-to-consonant coarticulation tends to exceed carryover coarticulation in these Australian languages. Accordingly, on the F2 variance measure, consonants tended to be more sensitive to the coarticulatory effects of the following vowel. Prosodic prominence of vowels was a less significant factor in general, although certain language-specific patterns were observed.