Verification of Hearing Aids by Comparing Real Ear Measurements and Word Recognition Scores

Abstract

Background and Objectives In this study, we introduce our method of hearing aid (HA) verification using real ear measurement (REM). We verified HAs that have gone through the fitting program using speech mapping REM; we then compared the outcome with word recognition scores (WRS) to evaluate functional gain. Subjects and Method Fifty-six patients of sensorineural hearing loss (81 ears) were enrolled in the study. In REM, if the gap between the target gain of HA and real ear aided response (REAR) was less than 10 dB SPL, fitting was considered successful. In speech audiometry, unaided maximum discrimination score (PB max), unaided WRS at 65 dB HL and aided WRS at 65 dB HL were measured. By comparing PB max and aided WRS at 65 dB HL, patients were sorted into best (n=15), good (n=57), and poorly (n=9) aided groups and analyzed for the successes of fitting. Fitting was deemed unsuccessful if REAR was ≥10 dB SPL lower than the target value of HA.Results The mean aided WRS at 65 dB HL of best, good and poorly aided groups were 85.6%, 77.3%, and 54.2%, respectively. There were statistically significant differences between all groups (<i>p</i>=0.019, 0.001, 0.002). The success rates of HA fitting showed significant differences at 0.5, 0.75, 1, 4 kHz of 55 dB SPL (<i>p</i>=0.023, 0.005, 0.003, 0.014), and at 4 kHz of 65 and 75 dB SPL (<i>p</i>=0.004, 0.001). The high WRS group showed sufficient gain at many frequencies. Conclusion Well fitted HAs can provide sufficient increase in speech intelligibility. Using the speech mapping REM is a great method to verify fitting of HA.