Background and Objective: To enhance the adherence of existing voice interventions for patients with presbyphonia, singing, as a leisure activity, has been suggested by existing reviews to be added to voice therapy. Current literature provides evidence of benefits of singing on aging voice. A singing-based voice therapy for patients with presbyphonia was developed. This study investigates the treatment and maintenance effect of this intervention in terms of vocal functions, voice quality and treatment adherence.

Methods: 12 older adult patients with presbyphonia were randomly assigned to either Singing or Control Group. The Singing Group practices five singing exercises derived from exercise science. The Control Group practices vocal function exercises. Both groups had eight intervention sessions, twice a week, with home practices twice daily. Assessment was conducted before the first session (pre-treatment), immediately after (post-treatment) and two months after the last intervention session (maintenance).

Results: All patients completed the pre-post assessment, with nine patients completed all three assessments.
For immediate treatment effect, breathiness rating of all patients decreased significantly (p = 0.03). Participants in the Singing Group showed significant increase in pitch range (semitone) (p = 0.05) and loudness range (p = 0.03). Significant improvement in Aging Voice Index (p = 0.04) was noted in the Control Group. Between two groups, the treatment effects and adherence were comparable with no significant difference. The home practice completion rates for adherence were over 80% for both groups.
For maintenance effect, all participants showed significant increase in pitch range measured in semitone (p = 0.02) and harmonic-to-noise ratio of sustained vowel /u/ (HNR/u/) (p = 0.04) over three timepoints. For Singing Group, HNR/u/ increased significantly overtime (p = 0.02). No significant maintenance effect was observed in Control Group, and no significant difference was found between groups.

Conclusion: While voice quality and aging voice-related quality of life significantly improved immediately after interventions, some vocal functions improved even after two months of the intervention. The treatment and maintenance effects between two groups were comparable, suggesting the singing-based intervention can be a valid intervention approach for patients with presbyphonia.