Effects of three parameters on speaking fundamental frequency.

Speaking fundamental frequency levels and usage (SFF, F0) are of interest to many investigators who study human speech and voice. Substantial research in the area has been carried out; common foci include SFF as related to infant cry, age, gender, adolescent voice change, language, race, voice pathology, and so on. Yet there still are a number of relationships which are not well understood and three of them will be addressed in this project. They involve the long-held notions that (1) a secular trend exists with SFF being lowered over time, (2) the use of university students in research of this type will create bias because they are physically different from average individuals, and (3) SFF can vary systematically for different types of speech (especially for oral reading and extemporaneous speaking). Experiments assessing these questions were carried out, but only certain of the postulates were supported. That is, while some evidence of a secular trend was found, it appeared inconsequential during the past quarter of this century; second, although university students were found to be slightly larger than a cohort approaching the average population, only minor vocal differences were found. Finally, it was observed that, in general, oral reading resulted in higher mean SFF's than those for spontaneous speech. However, this difference was not robust and, due to reversals, the resulting metric did not appear to be of good predictive value for individual speakers.