Objective study of the voice in a normal population and in dysphonia caused by nodules and vocal polyps

A study of the objective evaluation of voice was made of 100 voices of healthy adults and 60 with disphonia (nodules and polyps). A laryngostroboscopy and an acoustic analysis was made to everyone. A sustained vowel "a" was carried out and digitalized with Dr. Speech Science software. These parameters were estimated: fundamental frequency (Fo, according to gender), Jitter, Shimmer and glottic noise (NNE, HNR, SNR). In the healthy group Fo was 139.72 in men and 267.33 in women, jitter 0.24 and shimmer 2.10. In disphonic patients (nodules) Fo was 126.96 in men and 240.72 in women, jitter 0.35 and shimmer 3.25. In disphonic patients (polyps) Fo was 119.75 in men and 218.26 in women, jitter 0.50 and shimmer 4.34. These difference were statistically significant. Glottic Noise in healthy group was: NNE -13.62, HNR 24.07 and SNR 24.49; in disphonic patients (nodules) was: NNE -10.65, HNR 25.21 and SNR 25.55; in disphonic patients (polyps) was: NNE -8.24, HNR 29.63 and SNR 28.22. Only the difference in the NNE was statistically significant. We highlight the importance of objective evaluation of voice disorders.