Linguistic timing factors in combination.

This study attempts to determine the ways in which linguistic timing factors combine with each other in the production of English and specifically, to test and explore aspects of the timing model of Klatt [J. Acoust. Soc. Am. 59, 1208-1221 (1976)]. In two experiments the tensity feature of a sentence stressed vowel and the voicing of the following stop were changed along with a variable that alters the length of the VB syllable. The duration of both the vowel, V, and the following stop closure, C were measured. In the first experiment either one or two unstressed syllables are added to the word and in the second speaking tempo is changed. The significant results of both experiments are accounted for with a formal timing model that separately specifies (1) the Vm + C duration (where Vm = mean duration across the two vowels /i/ and /I/) depending on tempo or word length, (2) the ratio Vm/C depending on the voicing of the stop (/b/ or /p/), and (3) as a final ordered step, a rule that adjusts the vowel length by a constant ratio depending on the identity of the vowel. This integrated model provides for (1) the "incompressiblity" effects, (2) prosodic properties, and (3) the constant V/C ratios for values of the voicing feature found in perception experiments.