Comparison between the International Outcome Inventory for Hearing Aids Questionnaire and Real-Ear Measurement.

Introduction: The international outcome inventory for hearing aids (IOI-HA) is a questionnaire widely used to assess the subjective benefits of hearing aids. This study aimed to evaluate the relationship between IOI-HA outcomes and target mismatch in real-ear measurement (REM).

Methods: Thirty-four ears of 25 patients who had worn hearing aids were evaluated using the Korean version of the IOI-HA and REM after fitting for 2 months. Real-ear insertion gain (REIG) was measured at three different levels of input intensity - 50, 65, and 80 dB sound pressure level (SPL) - and a frequency range of 0.25-6 kHz. Factors 1 and 2 and total IOI-HA scores were compared with the mismatches of REIGs and target gains of REM.

Results: Factor 1, factor 2, and total IOI-HA scores were 14.6 ± 3.5, 11.4 ± 2.2, and 25.9 ± 5.1, respectively. The averages of the difference of REIGs and target gains in REM at 50, 65, and 80 dB SPL input levels were -3.1 ± 6.7, -2.3 ± 7.2, and -3.0 ± 8.2, respectively. Factors 1 and 2 scores of the IOI-HA showed significant correlations with target mismatch in REM at 1 kHz and 0.75 kHz frequencies, respectively. Total IOI-HA scores had significant correlations with target mismatches in REM at 0.75 and 1 kHz frequencies.

Conclusion: IOI-HA scores correlated with target mismatch in REM at mid frequencies. The IOI-HA can be a useful screening measure for evaluating the necessity of further adjustments in hearing aids through REM at mid frequencies.