Comparing the Diadochokinetic Rate in Farsi-Speaking Young and Older Adults

Speech Diadochokinesis (DDK) is defined as the ability to produce repetitive and fast speech movements. This study aimed at comparing the DDK rate between Farsi-speaking young and older adults. 

In this study, 244 normal adults (122 males and 122 females) were divided into two groups of young people (20-49 years) and elderly (50-69 years). DDK tasks was performed based on two ways: the participant was asked to produce /pa/,/ta/,/ka/,/pata/,/paka/,/taka/, and /pataka/ sounds in 5 s; and to repeat single syllable sounds (/pa/,/ta/,/ka/) 20 times, two syllables sounds (/pata/,/paka/,/taka/) 15 times, and a three syllables sound (/pataka/) ten times, separately and quickly. The independent T-test, one-way ANOVA, and Pearson correlation were used for data analysis.

The results indicated a significant negative and weak correlation between age and all syllables in the specified time (range: -0.139 to -0.254), and a positive and weak correlation between age and time with respect to the repetition of all syllables (range: 0.121 to 0.245). There was no significant difference between genders in both ways (P>0.05).

The results indicated different DDK rate between the young and elderly subjects that can be used as a benchmark for the diagnosis of disabled individuals in producing repetitive and fast oral movements and also as a basis for clinical assessments.