Glottal Features in Vocal Assessment Following Thyroidectomy

Objectives Vocal dysfunction is a frequent complication following thyroidectomy that can be associated with a negative impact on patients’ quality of life. Although the effect of thyroidectomy on acoustic features has been widely studied, the examination of glottal flow characteristics to assess vocal outcomes following thyroid gland surgery has not been included in empirical research, to date. The goal of our study was to evaluate early and short-term vocal outcomes following thyroidectomy based on the analysis of glottal acoustic features during speech production. Study design Prospective analytical study. Materials and methods We evaluated vocal outcomes in patients who underwent thyroidectomy between September 2021 and March 2022. We extracted glottal flow features from their vocal recordings preceding surgery and postoperatively at Day1 and Month1 postoperatively. The extraction of glottal features was performed using a signal processing-based approach. We extracted the following features: Open quotients (OQ1 and OQ2), Quasi-open quotient (QoQ), Closing quotient (ClQ), Amplitude quotient (AQ), Normalized Amplitude quotient (NAQ) and Speed quotients (SQ1 and SQ2).We included 39 patients. OQ2 and QoQ decreased significantly at Day1 and Month1. OQ1 and NAQ decreased significantly at Month1. ClQ remained stable at both postoperative assessments. AQ decrease was not significant at both dates. SQ1 increased at Day1 and Month1 but the change was not significant. SQ2 decreased significantly at both Day1 and Month1. OQ, QoQ, AQ, NAQ, and SQ2 did not recover at Month1. We noted that the decrease of SQ1 and SQ2 correlated significantly with the increase of the Voice Handicap Index-10 (VHI-10) at Month1. Conclusion The analysis of glottal acoustic features can be a reliable modality to detect vocal changes following thyroidectomy. Thyroidectomy was associated with a vocal dysfunction that was manifested by the decrease of open, amplitude, and speed quotients. Glottal features can present a potential tool to objectively assess the effect of thyroidectomy on vocal folds movements.