Bruce L. Smith
Dept. of Commun. Sci. and Disord., Northwestern Univ., 2299 Sheridan Rd., Evanston, IL 60208
Research with neuromotorically impaired adults and with normally developing children has suggested that duration and variability measures of speech may be indicators of neurological integrity. It is also important to determine whether these same measures have any implications regarding the speech production abilities of normal adults. The present study assessed the performance of normal adult subjects for several speech and nonspeech tasks to determine (a) whether normal adults can voluntarily reduce variability in their speech and (b) whether similar duration and variability relationships exist for speech and nonspeech (tapping and reaction time) tasks. The speech tasks included a control condition in which subjects repeated stimuli with no specific instructions, and an experimental task in which they were to be as consistent as possible in repeating stimuli in an attempt to minimize variability. Preliminary analyses indicate that the variability of speech segments did not tend to differ when comparing the control and experimental conditions. Relationships between duration and variability for the speech tasks and for the nonspeech tasks were quite comparable, with the correlations between these two measures not being very strong.