Acoustic Analysis of Four Common Voice Diagnoses: Moving Toward Disorder-Specific Assessment

Objectives. To assess treatment outcomes via acoustic voice laboratory measurements before and after intervention in patients with common voice problems and Determine if outcome sensitivity of certain voice laboratory measures varies with disorder type. Study Design. Retrospective and single-blinded. Methods. In this study, 40 patients with a single voice disorder diagnosis of either benign vocal fold lesions (lesions), primary muscle tension dysphonia (MTD-1), vocal fold atrophy (atrophy) or unilateral vocal fold paralysis (UVFP) underwent baseline testing, a single intervention-type (phonosurgery/voice therapy), and follow-up testing at uniform time points. Ten patients per diagnosis group were analyzed before and after treatment. Time-and frequency-based acoustic measures taken from vowels and sentences as well as patient-perceptual analysis (Voice Handicap Index-10) were reviewed. Results. Statistically significant improvements were observed for three of four groups. Patients with muscle tension dysphonia displayed an improvement in Cepstral Spectral Index of Dysphonia speech (CSID) (P < 0.05). Patients with lesions had improved Voice Handicap Index-10 (P < 0.05), cepstral peak prominence (CPP) vowel standard deviation (P < 0.05), and CPP speech (P < 0.05). Patients with atrophy did not demonstrate significant improvement in any measure. Patients with unilateral vocal fold paralysis showed an improvement in CSID speech (P < 0.05) and CPP speech (P < 0.05). In addition, strong effect sizes were observed for many of the acoustic parameters studied. Conclusions. For all groups except atrophy, treatment was successful in improving patient perception of voice handicap and/or some acoustic voice parameters. A disorder-specific response to frequency-based acoustic measures was found.