Effects of increased speaking rate on temporal and spectral information for coarticulated vowels

Abstract

As part of a larger study of the role of dynamic (time‐varying) spectral information in the perception of vowels, we are analyzing American English vowels spoken in bisyllables imbedded in a carrier sentence by one female who normally speaks rapidly. Eleven vowels in six /hə C1VC2/ contexts (C1 = b,d,g; C2 = d,t) were produced at the subjects' normal speaking rate and at a “rapid” rate (69% of normal sentence duration). Durations of test syllables were systematically reduced; rapid/normal ratios were 75% for CVd syllables and 83% for CVt syllables. Relative durations were well maintained; the correlation between rapid and normal syllable durations was +0.93, and showed only a slight curvilinear trend suggesting almost no limit of compressibility for the shortest vowels. Dynamic spectral structure and “target undershoot” is also being analyzed. Formant frequencies at three points—one‐third, one‐half, and two‐thirds through the vocalic nucleus—will be compared to explore whether “vowel‐inherent” spectral ch...