Severity of voice disorders: integration of perceptual and acoustic data in dysphonic patients.

Abstract

To analyze the correlation between acoustic measures and intensity of vocal deviation, and its discriminatory power in detecting the presence of vocal change, classifying the severity of the deviation and differencing the type of predominant voice. The sample comprised 186 patients with dysphonia. The vocal deviation from the vowel/ε/was evaluated by consensus between three speech language pathologists, using a Visual Analog Scale. We extracted the mean and standard deviation (SD) of the fundamental frequency (F₀), jitter, shimmer, and Glottal-to-Noise Excitation Ratio (GNE). Mean F₀ was negatively correlated with the degree of roughness and positively with the degree of tension. The F₀ SD was positively correlated with the overall, roughness, tension, and instability grades. The jitter and shimmer were positively correlated with all perceptual parameters. Only the GNE distinguished between healthy and dysphonic voices and rated the degree of breathiness. The shimmer separated rough voices from not rough voices. The mean F₀ was helpful to determine the degree of phonatory tension and to separate rough voices from breathy and strained voices. There is a correlation between the acoustic and auditory perceptual measures. The shimmer, the GNE, and F₀ SD can be used to detect roughness, breathing, and strain, respectively. The GNE and mean F₀ are useful to classify the degree of breathiness and strain, respectively. The mean F₀ distinguished between rough, breathy, and strained voices, with rough voices more severe compared to the other two.