The effect of emphatic stress on CV coarticulation

Abstract

The effect of emphatic stress on CV coarticulation was investigated in the speech of one male and one female native speaker of American English using locus equation slope as a measure of CV coarticulation. Stressed real word C1V2C2 tokens where C1=/b,d,g/ and V2=/i, I, e, ε, æ, u, o, ɔ, a/ were put in carrier sentences with <ub;-.2>the, <ub;-.2>thirty<ubx>, or <ub;-.2>two<ubx> preceding the test word. Each sentence was read three times in a normal manner and three times with emphasis on the test token. This resulted in a total of 486 tokens per speaker (3 stop consonants * 3 V1 contexts * 9 V2 contexts *2 emphasis patterns *3 repetitions). Locus equation slopes were derived by plotting F2 onset of C1 against V2 F2 mid-vowel frequency and fitting a regression line to data points. Consonant closure duration, V2 duration, F0, and amplitude were also measured. Despite a significant increase in the acoustic correlates of emphasis, locus equation slopes remained constant as a function of emphasis and varied as a function of place of articulation. This study provides further evidence of the stability of locus equation slopes as phonetic descriptors of stop place of articulation. [Work supported by NIH.]