[Hearing aids: objective and subjective evaluations of linear and nonlinear amplification users]

Abstract

Background: Sensorineural hearing impaired individuals benefit themselves with the use of nonlinear amplification, once the compression tries to reestablish the sensation of normal loudness. However, the literature is still controversial in relation to the benefits for speech recognition in users of linear and nonlinear hearing aids.

Aim: For this reason, the purpose of this study was to compare the performance of linear and nonlinear hearing aid users through objective and subjective evaluations, verifying the best circuit for hearing adaptation and speech recognition in silence and in noise.

Method: 21 bilateral hearing aid users, who had been using the hearing aid for at least 3 months, with 12 to 64 years of age and with mild to moderate-severe hearing losses were studied according to the type of amplification used, forming two groups: linear group composed by 10 linear hearing aid users; and nonlinear group, composed by 11 nonlinear hearing aid users. Speech recognition tests were applied in silence and in noise, as well as the International Outcome Inventory of Hearing Aids questionnaire.

Results: Statistically significant differences were not observed between the groups for the speech recognition tests, in silence and in noise, and for the questionnaire.

Conclusion: It can be concluded that no difference exists in the performance of linear and nonlinear hearing aids users, regarding the objective evaluations (speech tests) and the subjective evaluations (questionnaire), that indicate a better adaptation or a better speech recognition in silence or in noise.