Data of voice onset time (VOT) in the evaluation of the vocal signal of individuals with unilateral vocal fold paralysis

Abstract

The aim of this study is to verify the effectiveness of VOT (voice-onset-time) measure in subjects with vocal pathology. A study was carried out involving five subjects with unilateral vocal fold paralysis and a control subject, without vocal complaints and pathology. The Acoustic Theory of Speech Production by Fant (1970) was adopted. Connected speech samples including syllables with voiceless and voiced consonants stops, were acoustically analyzed and submitted to the perceptual evaluation (speech intelligibility). Subjects with unilateral vocal fold paralysis had been through laryngoscopic examinations. The subjects presented deviated VOT values for voiced consonants compared to the control subject, nevertheless, they produced sounds identified as voiced, in general. These results have shown the relevance of the VOT use in the evaluation of the vibratory action of vocal folds, since it can reveal the presence of efficient mechanisms of compensation for the voicing activity in subjects with glottal limitation on the opening and closing of the vocal folds.