Acoustical control of voice changes after surgery: an exploratory essay.

In this preliminary study, the authors try to validate the use of a quantitative method based upon the use of Long Term Average Spectra (LTAS) and indices of spectral (dis)similarity. The whole spectral information is used and an evolution ratio is introduced. The technique has been tested on 5 patients with organic lesions of the vocal cords (oedema, polypoid degeneration, hyperkeratosis, polyp, pseudocyst). Each patient has been recorded three times: the day before surgery, one and 5 weeks later. The obtained values suggest good correlation between the index variability and the magnitude of clinical change. The values obtained from the quantitative technique turn out to be well correlated with the evolution of the patients' state.