A preoperative speech therapy counseling will be carried out the day before the Total Thyroidectomy with the aim of informing patients about the possible conditions of the immediate post-operative period. Therefore, indications of vocal hygiene and hydration standards will be simultaneously administered, to be implemented from the first post-operative day.

Patients will undergo phoniatric follow-up in the immediate post-operative period, at 7 days, 1 month and 3 months post-operatively.

Patients who, at follow-up checks, should present the symptoms of functional post-thyroidectomy syndrome will undergo a cycle of post-operative speech therapy of 8 sessions.

Using the Multidimensional Voice Program, the Fundamental Frequency (F0, Hz) will be analyzed in the central 3 seconds of a sustained /a/.

Using the Multidimensional Voice Program, the noise/harmonics ratio (NHR) will be analyzed in the central 3 seconds of a sustained /a/.

Using the Multidimensional Voice Program, the Jitter (%) will be analyzed in the central 3 seconds of a sustained /a/.

Using the Multidimensional Voice Program, the Shimmer (%) will be analyzed in the central 3 seconds of a sustained /a/.

The patient will be instructed in the production of a sustained /a/ from the lowest to the highest note, from minimum to maximum intensity. In this case, the Minimum frequency (Flow) will be analysed.

The patient will be instructed in the production of a sustained /a/ from the lowest to the highest note, from minimum to maximum intensity. In this case, the Maximum frequency (Fhigh) will be analysed.

A questionnaire called Voice Impairment Score (VIS) will be used, created specifically to investigate the frequency of voice alterations. The VIS consists of 10 items and can vary from a minimum score of 0 (no vocal alteration) to a maximum of 40 (maximum voice disturbance).