Voice alterations after thyroid surgery in the absence of recurrent laryngeal nerve injury

BACKGROUND: The aim of this study is to evaluate voice quality in patients undergoing thyroidectomy without recurrent laryngeal nerve injury, using objective acoustic analysis before and three months after surgery.METHODS: Thirty-five patients who underwent thyroidectomy without evidence of vocal fold paralysis or nerve injury were included. Voice samples were recorded preoperatively and three months postoperatively using Voxplot software. Acoustic parameters analyzed included F0, jitter, shimmer, HNR, CPPS, GNE, ABi, and AVQI, along with maximum phonation time (MPT). Recordings were performed in a quiet environment with an external microphone under standardized conditions.RESULTS: Three months after surgery, a significant improvement was observed in noise-related acoustic parameters (HNR, CPPS, and GNE; P<0.05), while F0, jitter, and shimmer remained stable. Maximum phonation time increased significantly. These findings suggest a reduction in glottal noise and an improvement in the harmonic structure of the voice signal, may be related to laryngeal decompression following thyroid volume reduction.CONCLUSIONS: In patients without recurrent laryngeal nerve injury, postoperative voice alterations after thyroidectomy are mainly attributable to mechanical and anatomical rather than neurological factors. Objective acoustic analysis enables the identification and monitoring of these changes, supporting targeted follow-up and voice rehabilitation strategies. Post-thyroidectomy voice phenomena are multifactorial, and improvement in vocal quality may result from both glottic decompression and neuromuscular compensatory mechanisms.