Comparison of Voice Changes After Thyroidectomy Between Normal Adult and Elderly Populations

Background and Objectives Voice changes after thyroidectomy have a significant impact on patients’ quality of life, yet age-related differences remain insufficiently clarified. This study aimed to compare postoperative voice changes between younger and older adults without laryngeal nerve injury.Materials and Method A total of 317 patients (200 younger adults, 117 older adults) were evaluated preoperatively and within 2 weeks after surgery. Acoustic parameters (fundamental frequency [F0], jitter, shimmer, noise-to-harmonic ratio [NHR], speaking fundamental frequency [SFF]), voice range profile (VRP), electroglottography (EGG), and aerodynamic parameters (maximum phonation time [MPT], mean airflow rate [MFR], pressure of subglottal [Psub]) were assessed. Paired t-tests were used for within-group comparisons, and Welch’s t-tests and analysis of covariance (ANCOVA) were applied for between-group analyses while controlling for sex effects.Results In the older group, the F0 significantly decreased after surgery (p=0.033). The SFF decreased in both groups, but the reduction was greater in older adults, showing a significant between-group difference (ANCOVA, p=0.004). Jitter and shimmer showed no significant changes, while NHR significantly increased only in the older group (p=0.039). VRP decreased in both groups without significant between-group differences (p>0.05). EGG showed a significant increase in contact quotient only in younger adults (p=0.019), whereas no changes were observed in older adults. Aerodynamic parameters (MPT, MFR, Psub) did not show significant changes in either group, although a sex effect was noted for MFR (p=0.011).Conclusion After thyroidectomy, older adults demonstrated greater reductions in fundamental frequency and increased noise components, with limited improvements in glottal contact compared to younger adults. In contrast, VRP decreased similarly across age groups. These findings indicate that age plays a critical role in postoperative voice outcomes, highlighting the need for age-specific preoperative counseling and early postoperative voice management.