Seyyede Zohre Mousavi - Department of Speech Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
Azar Mehri - Department of Speech Therapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran.
Delaram Nabavi - Department of Speech Therapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran.
Marziyyeh Faraji - Department of Speech Therapy, University of Welfare and Rehabilitation Sciences, Tehran, Iran.
Saman Maroufizadeh - School of Nursing and Midwifery, Guilan University of Medical Sciences, Rasht, Iran.

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, ۲۴۴ normal adults (۱۲۲ males and ۱۲۲ females) were divided into two groups of young people (۲۰-۴۹ years) and elderly (۵۰-۶۹ 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 ۵ s; and to repeat single syllable sounds (/pa/,/ta/,/ka/) ۲۰ times, two syllables sounds (/pata/,/paka/,/taka/) ۱۵ 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: -۰.۱۳۹ to -۰.۲۵۴), and a positive and weak correlation between age and time with respect to the repetition of all syllables (range: ۰.۱۲۱ to ۰.۲۴۵). There was no significant difference between genders in both ways (P>۰.۰۵). 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.

Diadochokinetic, Elderly, Young, Persian adults