Efficacy of SNR Loss as a Clinical tool for Hearing Aid Evaluation

Abstract

Aim: To evaluate the efficacy of SNR loss as a clinical tool for hearing aid evaluation. Objectives: To compare the SNR-50 across participants with normal hearing, minimal SNHL and mild SNHL. To estimate a cut-off criterion for SNR loss to demarcate the need for amplification device. To compare the traditional hearing aid evaluation approach based on testing speech in quiet and the alternate approach of hearing aid evaluation based on SNR loss. Method: SNR-50 and SNR loss estimation was done followed by administration of self assessment of hearing handicap questionnaire rating. A cut-off criterion to decide whether hearing aid is required or not was set based on the scores of questionnaire rating. Hearing aid trials using both approaches were counter balanced among the participants. Study Sample: 20 participants with normal hearing, 11 with minimal SNHL and 11 with mild SNHL for estimating cut-off criterion. Ten participants with moderate SNHL for comparing two approaches of hearing aid trial. Results: SNR-50 of the ears with minimal and mild SNHL was significantly higher than the ears with normal hearing. However, there was no significant difference between mean SNR-50 of ears with minimal and mild SNHL. SNR loss of 5.50 was estimated as cut-off criterion to decide hearing aid candidacy. There was no significant difference between the two hearing aids when the traditional approach was used whereas when the SNR loss approach was used there was a significant difference observed between the two hearing aids. Conclusion: SNR losshas substantial clinical implication in hearing aid prescription.