Effectiveness of Immersive Oral Muscle Training on Pronunciation in Older Adults: A Randomised Trial

Pronunciation difficulties in older adults frequently stem from age-related weakening of the oral muscles, necessitating accessible and engaging training approaches. This study aimed to evaluate the effectiveness of oral muscle strengthening exercises using immersive educational content to improve pronunciation in older adults.

Individuals aged 65 years and older were screened using the Speech Mechanism Screening Test. Those classified as normal were assigned to receive oral muscle strengthening exercises combined with realistic educational content twice per week for 6 weeks. To assess improvements in pronunciation, the following measures were evaluated: Total Percentage of Consonants Correct (PCC), Proportion of Whole-Word Correctness (PWC), Phonological Mean Length of Utterance (PMLU), Proportion of Whole-Word Proximity (PWP) and Percentage of Vowels Correct (PVC). Additionally, phonological error patterns were analysed.

According to repeated-measures ANOVA, the intervention group showed significantly greater improvements than the control group post-intervention in PCC (from 97.87 at baseline to 98.99 post-intervention, p = 0.003), PWC (from 0.91 to 0.96, p < 0.001) and PMLU (from 8.49 to 8.53, p = 0.03). Vowel change errors significantly decreased (from 0.80 to 0.40, p = 0.04).

Oral muscle strengthening exercises that incorporate immersive educational content are effective in improving selected pronunciation outcomes in older adults. These findings therefore suggest that these exercises may serve as feasible interventions for enhancing speech intelligibility in this population.