Effects on Voice Quality of Thyroidectomy: A Qualitative and Quantitative Study Using Voice Maps

Area of Science:

• Otolaryngology
• Speech-Language Pathology
• Acoustic Analysis

Background:

• Thyroidectomy, the surgical removal of the thyroid gland, poses a risk to vocal function due to the proximity of laryngeal nerves.
• Previous research has focused on voice range changes post-thyroidectomy, with limited exploration of voice quality.
• Voice quality alterations after thyroid surgery can be multifaceted and are not fully understood.

Purpose of the Study:

• To investigate the impact of thyroidectomy on voice quality using acoustic and electroglottographic (EGG) measures.
• To apply an exploratory approach to identify potential changes in various voice metrics post-surgery.
• To correlate objective voice measures with subjective patient complaints.

Main Methods:

• A retrospective voice-mapping analysis was performed on 57 patients undergoing thyroid surgery.
• Objective voice quality assessment using six acoustic and EGG metrics was conducted pre-surgery and two months post-surgery.
• Comparative voice maps were generated to analyze pre- and post-intervention changes.

Main Results:

• Statistically significant changes indicating a decline in voice quality were observed across most metrics post-thyroidectomy.
• Individual metric changes were generally small in effect size, lacking clinical relevance.
• Statistical clustering revealed that changes were primarily related to increased phonatory instability.
• Partial thyroidectomy showed more uniform results than total thyroidectomy; perioperative damage type did not impact voice quality.

Conclusions:

• Thyroidectomy is associated with increased phonatory instability, affecting both acoustic and EGG voice metrics.
• Clustered voice metrics demonstrated a stronger correlation with patient-reported voice complaints than individual metrics.