Alternating and Sequential Motion Rates for Normal Persian-Speaking People Aged 60-80 Years in Isfahan City, Iran

Speech is a complex motor skill that requires control and coordination of different systems such as respiration, vocalization, and articulation. Diadochokinesis is one of the oral motor measurements which is calculated per time. Diadochokinesis data are useful in determining the physiological state of speech production. This is an indicator for assessment, diagnosis and treatment of patients with neurological speech disorders. General health can affect the speed and accuracy of body and oral motor by age. Considering that there are no data on this criterion in Persian-speaking elderly people, in this study, the average rate of alternating and sequential motion rates (AMR and SMR) of the syllables were studied in a 60- to 80-year old adults in Isfahan City, Iran.
42 participant repeated /pa/, /ta/, /ka/, and /pataka/ sequences, quickly and accurately for five seconds with one minute rest between each task. Speech samples were collected using a digital recorder, then rate of diadochokinesis was calculated in syllable per seconds.
Mean rate of each task per seconds was obtained as 4.06, 3.90, and 3.66 syllable per seconds for /pa/, /ta/, /ka/, and /pataka/ sequences, respectively. The reduction in velocity was seen from anterior to posterior. Mean alternating motion rate was 1.58 syllable per seconds for /pataka/ sequence.
This study compensates the lack of normal information via providing descriptive results of the diadochokinesis rates of Persian-speaking Isfahanian elderlies. Therefore, a better and more reliable judgment of speech movement rate abnormalities and motor speech disorders in elderly people aged 60-80 years would be possible. The results confirm the inter-lingual differences of diadochokinesis, slowness of rates by aging, and the gradual reduction of the diadochokinesis rate towards the back of the oral cavity.