Oral diadochokinetic rates across languages: Multilingual speakers comparison

Oral diadochokinetic production in children with typical speech development and speech-sound disorders

BACKGROUND

AIMS: To investigate the developmental trajectory of the rate and perceptual assessment of oral diadochokinesis (DDK) in typically developing children compared with adults. Also to examine the characteristics of DDK productions in children with speech sound disorders (SSD) and the relationship between DDK production and percentage of consonants correct (PCC).

METHODS & PROCEDURES

Participants were 316 typically developing children and 90 children with SSD from 3 to 9 years old, as well as 20 adults with normal speech. The mono-, bi- and trisyllabic nonsense strings containing Korean tense consonants and the vowel [a] were used for DDK tasks. The number of iterations per s was measured as the DDK rate for each stimulus. The perceptual assessment of DDK productions was also performed for regularity, accuracy and rate.

OUTCOMES & RESULTS

The DDK rates increased throughout childhood, but the oldest children, 9-year-olds in the current study, did not achieve adult-like rates for all mono- and trisyllabic strings. Children with SSD also did not show significant differences from typically developing children when the DDK productions were analysed using only accurate tokens. The PCC of children with SSD showed higher correlations with regularity, accuracy and rate of perceptual ratings than the timed DDK rate.

CONCLUSIONS & IMPLICATIONS

This study highlighted the fact that the comprehensive evaluation of DDK productions may provide even more useful information about children's oral motor skills.

WHAT THIS PAPER ADDS

What is already known on the subject Rates of DDK reflect the motor skills of the articulatory systems independently of phonological skills; therefore, the tasks are widely used in the diagnostic evaluations of speech disorders in both children and adult populations. However, a substantial number of studies have questioned the validity and usefulness of DDK rates for evaluating speech abilities. Also, the literature suggested that the measure of DDK rate alone does not provide a clear and useful indication of children's oral motor skills. DDK tasks should be analysed in terms of accuracy and consistency as well as rate. What this paper adds to the existing knowledge The literature reporting normative DDK performance has mainly been based on English speakers. As different consonants have different temporal characteristics, the linguistic and segmental features of DDK tasks can impact the DDK rate. This study established a norm for DDK rate for Korean-speaking children and investigated the developmental trajectory of DDK performance in typically developing children compared with adults. This study suggested that the comprehensive evaluation of DDK productions may provide even more useful information about children's oral motor skills by examining the characteristics of DDK productions in children with SSD. What are the potential or actual clinical implications of this work? This study provided normative data of young Korean-speaking children aged 3-9 years. Normative data in children under 5 years of age are valuable given that the majority of children referred for speech difficulty assessments are between 3 and 5 years of age, but only a few studies have provided the normative data in young children. This study showed that many children could not complete DDK tasks correctly and provided additional support for the notion that other aspects of DDK performance, including accuracy and regularity, may yield more useful diagnostic indications than timed DDK rates alone.

Automated Analysis of Phonoarticulatory Diadochokinesis in Tamil Speakers

OBJECTIVES

Diadochokinetic rate (DDK) quantifies the laryngeal and oral muscle coordination, but there are insufficient baseline evidence exist, that limits the effectiveness of computerized DDK evaluation in assessing motor speech control. In the end, this study will give normative data on age and gender effects on both oral and laryngeal DDK in Tamil speakers.

STUDY DESIGN

Cross sectional Study.

METHOD

A total of 150 participants in the age range of 17-25;11 years were divided into three groups- Group I (17-19;11 years), Group II (20-22;11 years) and Group III (23-25;11 years) with equal number of male and female. The participants were asked to produce /pʌ/, /tʌ/, /kʌ/, /pʌtʌkʌ/, /a/& /i/ for 5 seconds in Motor Speech Profile (MSP), at Computerized Speech Lab (CSL). The parameters such as Average DDK period (DDKavp), average DDK rate (DDKavr), Standard deviation(SD) of DDK period (DDKsdp), Coefficient of Variation of DDK period (DDKcdp), Perturbations of DDK period (DDKJit) and Coefficient of variation of the DDK peak intensity (DDKcvi) were selected for analysis.

RESULT

The effect of age was noted for Laryngeal DDK, the DDKavr of /a/ (P = 0.008) and /i/ (P = 0.04) and DDKcdp for /a/ (P = 0.01), the mean values of those parameters are higher for the individuals within the age of 23-25;11 years but no difference was observed across the age for Oral DDK. The effect of gender was noted for Laryngeal DDK, DDKsdp (P = 0.007) and DDKJit (P = 0.04) for /i/, the mean values are higher for females. For Oral DDK, DDKJit (P = 0.006) for /kʌ/ the mean values are higher for females.

CONCLUSION

The normative data has been established for the Tamil speakers. Age specific normative should be used during the DDK evaluation of speech disorders in MSP, CSL.

Impact of oral motor task training on corticomotor pathways and diadochokinetic rates in young healthy participants

Background

Studies addressing the training‐induced neuroplasticity and interrelationships of the lip, masseter, and tongue motor representations in the human motor cortex using single syllable repetition are lacking.

Objective

This study investigated the impact of a repeated training in a novel PaTaKa diadochokinetic (DDK) orofacial motor task (OMT) on corticomotor control of the lips, masseter, and tongue muscles in young healthy participants.

Methods

A total of 22 young healthy volunteers performed 3 consecutive days of training in an OMT. Transcranial magnetic stimulation was applied to elicit motor evoked potentials (MEPs) from the lip, masseter, tongue, and first dorsal interosseous (FDI, internal control) muscles. MEPs were assessed by stimulus–response curves and corticomotor mapping at baseline and after OMT. The DDK rate from PaTaKa single syllable repetition and numeric rating scale (NRS) scores were also obtained at baseline and immediately after each OMT. Repeated‐measures analysis of variance was used to detect differences at a significance level of 5%.

Results

There was a significant effect of OMT and stimulus intensity on the lips, masseter, and tongue MEPs compared to baseline (p < .001), but not FDI MEPs (p > .05). OMT increased corticomotor topographic maps area (p < .001), and DDK rates (p < .01).

Conclusion

Our findings suggest that 3 consecutive days of a repeated PaTaKa training in an OMT can induce neuroplastic changes in the corticomotor pathways of orofacial muscles, and it may be related to mechanisms underlying the improvement of orofacial fine motor skills due to short‐term training. The clinical utility should now be investigated.