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Summary Objective This study aims to (1) determine the cutoff values of the overall severity (OS) of vocal deviation on the visual analog scale (VAS) based on the ratings of the numerical scale (NS); and (2) verify the power of discrimination of these cutoff values according to different degrees of vocal deviation. Study Design This is a prospective study. Methods The auditory-perceptual evaluation was performed by four speech-language pathologists who used two protocols with different scalar properties: the VAS and the 4-point NS. Vocal samples from142 women and 69 men, plus 10% of repetition, with and without vocal complaints, ranging from 19 to 60 years were included. The analyzed speaking task was the counting from 1 to 10. For both protocols, the judges rated the OS. Results Based on the correspondence between the two scales, the cutoff values of the OS on the VAS obtained were 35.5, 50.5, and 90.5 points. The 35.5 value corresponds to the cutoff point between normal variability and mild/moderate vocal deviations; the 50.5 value corresponds to the cutoff point between mild/moderate and moderate vocal deviations; the 90.5 value corresponds to the cutoff point between moderate and severe deviations. Areas under the receiver operating characteristic curve for the three cutoff values were 0.918, 0.948, and 0.970, respectively. Conclusions The cutoff values of the OS on the VAS were obtained, and the areas under the ROC curve showed that all the three cutoff points had excellent accuracy that represents a higher power of discrimination of different degrees of vocal deviations.

Although the latency between the initiation of thyroarytenoid electrical activity and the onset of phonation generally is increased in patients with adductor laryngeal dystonia, there is disagreement about whether there is overlap of latency values in these patients and normal subjects. The goal of this article was to compare the severity of dysphonia with the latency between electrophysiological activation of the thyroarytenoid muscle (TA) and the onset of phonation in patients with adductor laryngeal dystonia and compare the values with normal controls. Twenty-one patients with adductor dystonia and 15 control patients underwent laryngeal electromyographic (EMG) examination of the left TA. We measured the latency from initiation spike of the electric activity of the TA muscle to the onset of phonation. Three speech-pathologists/voice specialists arrived at a consensus to rate the perceptual evaluation of voice quality for the study group. The average latency measured for patients with mild dysphonia was 332 milliseconds, for moderate dysphonia was 426 milliseconds, and for the severe dysphonia was 792 milliseconds. We used the Spearman's correlation test to compare the latency time values and the dysphonia's degree of severity (P0.05). Latency was significantly and directly related to the degree of severity of dysphonia.