Phrase-level timing patterns in English: effects of emphatic stress location and speaking rate

Phrase-level timing patterns in the utterance Bob hit the big dog were studied as a function of emphatic-stress location at two speaking rates. Five emphatic-stress conditions were defined: emphasis on each of the four content words, and one condition with no emphatic stress (neutral emphasis). Three subjects produced twenty repetitions of each condition at both rates. Results showed (1) the effect of emphatic stress on segment duration was not confined to the emphasized segments, but was manifest in nonemphasized segments as well; (2) when emphatic stress occurred near the beginning of the utterance, segment durations toward the end of the utterance were shortened relative to the duration of these segments in the neutral-emphasis utterance; however, for emphatic stress late in the utterance, beginning segments were not so modified; (3) the duration correlate of emphasis varied with position-in-utterance; and (4) increased speaking rate reduced or eliminated timing contrasts observed at the conversational rate, and affected the utterance-final segment differently from segments in other utterance positions.