[Acoustic study of sustained vowels made by patients with recurrent nerve paralysis after thyroidectomy]

The objective of this work is to evaluate the consequences of thyroid surgery on the voice of patients suffering from recurrent paralysis. The consequences of the surgery are evaluated using a corpus of sustained vowels in order to identify the various disruptions that this procedure may produce. This research also looks for possible compensatory and/or readjustment strategies that can be used by a patient alone and with the help of speech therapy. Acoustic measurements considered are fundamental frequency (F0), Harmonics-to-Noise Ratio (HNR), and vowel space area. This is a longitudinal study, as all patients are recorded once a month during three months after surgery. Results reveal a modification of all parameters in the early recording stages. However, time and speech therapy contribute to obtaining expected values of the measured parameters, and thus to improvement of vocal quality.