Acoustic analysis and self-assessment of changes in the voice after thyroidectomy

INTRODUCTION: A patient's voice, after a thyroidectomy uncomplicated by recurrent laryngeal nerve damage, may undergo both objective and subjective changes. The intensity and duration of these changes are unclear. The aim of this study was to conduct a subjective and acoustic analysis of the voice in patients after a thyroidectomy uncomplicated by recurrent laryngeal nerve damage. MATERIAL AND METHODS: A prospective study was performed at an endocrinological surgery clinic in Poland between 2018 and 2019. The study included 70 patients who had undergone a thyroidectomy due to noncancerous goitre. The Voice Handicap Index was used for a subjective assessment of the voice. An acoustic analysis was performed using the DiagnoScope Specjalista software, designed for a comprehensive assessment of the voice. A three-stage laryngological examination was performed. RESULTS: The mean age of the participants was 53 years (71% women and 29% men). Most of the patients (80.0%) subjectively assessed their vocal impairment as minor, 18.6% as moderate and 1.4% as severe. The patients assessed the physical state of their voice as the worst. The short-term parameters obtained through an acoustic analysis differed significantly between the subsequent measurements and were worst on the second day after the operation. The changes subsided six months after the operation. Likewise, a significant improvement in the long-term parameters was observed six months after the operation; specifically, the phonation time (15.11 vs 12.64 vs16.14) and the performance index (7.91 vs 6.50 vs 9.04). No significant changes were observed between each measurement in terms of the no phonation index, breaks in phonation index and the F0 modulation index. CONCLUSIONS: Voice impairment after a thyroidectomy is frequent, according to a subjective assessment, and has been confirmed by an acoustic analysis of the short- and long-term parameters of the voice. These changes usually subside six months after the operation. Some patients require logopaedic support to normalise their voice emission technique.