Comparison of diadochokinesis in Kannada-speaking adults who do and do not stutter

In the context of limited understanding of the objective measurement of diadochokinesis in adults with stuttering, the study aimed to compare the oral diadochokinetic and laryngeal diadochokinetic rates between adults who stutter and adults who do not stutter. The study further examined the effect of lexicality (real words vs. non-words) in oral diadochokinetic tasks.

Using Praat software, oral (oral diadochokinetic rate, consonant-vowel duration, and inter-syllabic duration) and laryngeal diadochokinetic rates were examined among 35 adults who stutter and 35 age- and gender-matched adults who do not stutter. Further, the effect of stimuli (real word vs. non-word) during oral diadochokinetic tasks was also examined.

Significant differences were noted between groups for monosyllabic oral and laryngeal diadochokinetic rates, but not during bi- and tri-syllabic diadochokinetic tasks, suggesting potential differences in speech-motor control between the groups. There was no significant difference between groups in consonant-vowel duration and inter-syllabic duration. In contrast to adults who do not stutter groups, a significant difference was observed with adults who stutter producing bi-syllabic real words faster than the non-words.

The present study emphasises the importance of using the dual diadochokinetic protocol (oral and laryngeal diadochokinetic), incorporating both real and non-word oral diadochokinetic tasks during clinical evaluations.