Oral-diadochokinetic rates for Tamil-speaking healthy ageing population: Non-word versus real-word repetition (dual protocol).

Oral diadochokinetic (DDK) tasks assess how quickly and accurately speakers can repeat syllables, reflecting oromotor coordination and articulatory control. This study aimed to provide insights into healthy aging among Tamil speakers using the sequential motion rate (SMR) task, examining how age and gender influence diadochokinetic (DDK) measures. It also compared DDK performance between real-word and non-word stimuli using a dual protocol. Eighty healthy Tamil-speaking individuals aged 50 to over 90 years were divided into four age groups (50-60, 61-70, 71-80, and 80+ years). Each participant repeated monosyllables (/pa/,/ta/,/ka/) and trisyllables (/pataka/), along with real trisyllabic words (/padagu/,/kadamai/) over 10-second intervals. DDK rates (syllables per second) were calculated using a count-by-time method. The alternating motion rate (AMR) for monosyllables/pa/,/ta/, and/ka/averaged 6.7 (SD = 1.2), 6.5 (SD = 1.4), and 6.4 (SD = 1.4) syllables per second, respectively. For the SMR task with/pataka/, a mean of 5.4 syllables per second (SD = 1.0) was observed. No significant gender differences were found. Younger individuals demonstrated faster rates, indicating that aging is associated with reduced articulatory speed. Notably, real-word repetition (e.g.,/padagu/) was faster than non-word (/pataka/) repetition in dual protocol tasks. Real words were repeated more rapidly than non-words, supporting the dual-protocol approach for evaluating articulatory performance in older adults. These results also offer preliminary Tamil-specific normative data to guide clinical evaluation and future research. [ABSTRACT FROM AUTHOR]