Assessment of effectiveness of acoustic analysis of voice for monitoring the evolution of vocal nodules after vocal treatment

Abstract

In the present study, we report the results of acoustic analysis of voice in 97 patients diagnosed with vocal nodules before and after the vocal logopedic treatment, to evaluate its effectiveness in monitoring the evolution. We analyzed five parameters: the mean fundamental frequency (F0) and its standard deviation, jitter, shimmer, and normalized noise energy (NNE). Our results indicate that most patients showed a reduction of fundamental frequency, an increase of perturbation (jitter and shimmer), and an increase of NNE before the treatment. We did not find any statistically significant relationship between previous values of the five parameters analyzed and the clinical course. We did not find significant differences between the two groups (with and without clinical improvement) in the evolution of any of the five parameters, although these differences were greater in the case of jitter. We conclude that the acoustic analysis of voice can be useful as a complementary tool in the diagnosis of vocal nodules, but the parameter values analyzed before treatment did not correlate with the clinical course and we believe that its usefulness in the evaluation of results after the vocal treatment is limited.