Fundamental frequency declination over changes in length
Carole E. Gelfer, Katherine Safford Harris, René Collier, Thomas E. Baer · The Journal of the Acoustical Society of America · 1983
The study of F0 declination affords the opportunity to study speech organization over large linguistic and temporal units. Of particular interest is how changes in utterance conditions are reflected as variations in the acoustic realization of F0. We have examined fundamental frequency, subglottal pressure and laryngeal muscle activity during utterances that varied systematically in overall length. Specifically we find that, while initial F0 values increase as a function of length, the rate of decline in F0 remains essentially invariant. That is, a speaker may prepare for and/or signal anticipated utterance length by increasing initial F0, but overall declination does not appear to be reorganized on the basis of this initial adjustment. We find too, that both tricothydroid and Ps activity correlate with the magnitude of the initial F0 changes and that the overall decline in Ps mirrors the F0 declination. Our impression is that a speaker has some expectations regarding changes in fundamental frequency over time, and that these changes are anticipated by making appropriate adjustments in initial conditions. These adjustments may, in fact, represent the extent to which declination is under speaker control. [Work supported by NINCDS and BRS grants.]