Differences in acoustic characteristics of stress patterns in American English

This study examined the differences between acoustic characteristics of lexical and emphatic stress patterns of American English in terms of changes in fundamental frequency (F0), duration, and amplitude of the stress patterns, and identified the most important acoustic characteristics among them. Speech samples were recorded from 13 randomly selected women (M=23.9 yr., SD= 1.7) who spoke American English as their first language. The speech samples were recorded using Computerized Speech Lab (CSL) Model 4300B with a 16-bit processor at a sampling rate of 44.1 kHz. Acoustic analyses of the lexical stress and emphatic stress patterns were performed. Statistical analyses showed a significant effect for the stress patterns and F0, duration, and amplitude; a significant effect for the stress types and F0, duration, and amplitude; and a significant interaction between the patterns and types. Based on the effect size, it can be concluded that duration appeared to be a more important acoustic character than amplitude or F0 in differentiating the lexical and emphatic stress patterns.