The Influence of Auditory Feedback and Vocal Rehabilitation on Prelingual Hearing-Impaired Individuals Post Cochlear Implant

Abstract

Objective. To verify changes in the perceptual and acoustic vocal parameters in prelingual hearing-impaired adults with cochlear implants after vocal rehabilitation. Hypothesis. Auditory feedback restoration alone after cochlear implant is not enough for vocal adjustments. A targeted and specific voice therapy intervention is required. Study Design. Prospective and pre-post repeated measures design. Methods. Twenty literate adults with severe to profound prelingual bilateral sensorineural hearing loss participated in the study; individuals were implanted late and were fluent users of oral language. Ages ranged from 17 to 48 years. All individuals presented normal results in laryngoscopy, and hearing thresholds with the cochlear implant were over 40 dB HL. Individuals were randomly distributed into two groups: Group 1 (treatment group) and Group 2 (control group), both with ten patients each, five men and five women, matching mean age and hearing deprivation time before the cochlear implantation. Patients from Group 1 underwent a protocol of vocal therapy including 12 individual sessions with the same clinician. Group 2 only underwent vocal recordings. The vocal recordings occurred before and after the participation in the therapy protocol for Group 1 and after the same period, 3 months later, without any intervention, for Group 2. The recording sessions used the Consensus Auditory-Perceptual Evaluation of Voice protocol sentence reading and emission of sustained vowel /a/. Auditory-perceptual evaluation of voices was performed by three judges, and the acoustical analysis used the Praat program. Results. Statistically significant reductions in the overall vocal degree, vocal instability, and degree of resonance change were observed after vocal rehabilitation in Group 1. Statistically, individuals from Group 1 did not differ in regard to the modification of acoustic parameters. Group 2 did not present significant changes in any of the analyzed parameters. Conclusions. The cochlear implanted adults submitted to vocal rehabilitation presented changes in the auditory-perceptual parameters, with reduction of the overall voice severity, vocal instability, and degree of resonance after vocal intervention. There were no changes in the acoustic parameters in the implanted prelingual hearing-impaired adult subjects.