When (if ever) does speaking rate become an essential variable in speech production

Abstract

In a previous paper [G. Weismer, J. Acoust. Soc. Am. Suppl. 1 73, S65‐S66 (1983)] we presented evidence that conversational and very fast speaking rates have virtually identical relative timing characteristics, thus supporting the notion of relative timing as a nonessential variable in speech production. In the present paper we replicate these findings and extend the analysis to the case of very slow speaking rates. In addition, measures of fundamental frequency contour and formant transition rate are studied to determine how their form may be altered by changes in speaking rate. Because slow speaking rates are often used as a strategy in rehabilitation of various speech disorders, it is important to know if the form of various vocal tract outputs is disrupted by unusually slow rates. Recent biomechanical studies indicate that slow rates may require unique control strategies, thus implying that a critical value of the nonessential variable speaking rate may be demonstrated experimentally by requiring normal speakers to produce speech at very slow rates. [Work supported by NIH.]