Comparision of oral diadochokinetic rates in the normal and aging population

Given that many perceive speech as becoming slow with aging, and that several studies have observed diadochokinetic rate reductions (although insufficient screening of subjects), it is of diagnostic importance to determine the presence of reductions due to aging. Rosenbek and LaPointe (1981) believe that senescent individuals "naturally become weaker and slower and that these changes need not to be seen as pathologic nor do they need to be treated" (p. 165). However, the present research endeavor posits that any weakness, slowness, or lack of coordination in motor speech should be indicative of an underlying disorder, not aging. The purpose of this investigation was to provide an analysis of motor-speech coordination (through utilization of oral diadochokinesis) for young and senescent individuals, as well as male and female, and to investigate the effects of the task (monosyllabic and trisyllabic). Currently, normal age-related changes (i.e., nonpathologic) on speech performance are uncertain, as most of the accepted clinical norms for assessing motor speech processes are based on observations of children and young adults (Parnell & Amerman, 1987). Parnell & Amerman (1987), state that "a comprehensive database for clinical definition of speech normality in the elderly remains far from complete" (p. 340). A more inclusive profile of speech parameters during aging is needed in order to understand the effect of age upon the speech process, and to facilitate the development of speech norms of the aging to serve as more sensitive indices for clinical evaluation of the aging population (Parnell & Amerman, 1987). This study addressed age and gender effects upon the speech parameter of oral diadochokinetic abilities. The experimental questions in this study were:

1. Are there significant differences in the oral diadochokinetic (DDK) rates between two age groups (20 to 30 and 65 to 75 years)?

2. Are there significant differences in the DDK rates when comparisons are made between males and females, and are there gender by age interactions?

3. Is there a significant correlation between subject speech rate on monosyllabic DDK tasks and the trisyllabic DDK task?