comparing the diadochokinetic rate in farsi-speaking young and older adults

Objectives: 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. methods: 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. results: 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). discussion: 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.