Frequency Importance Functions in Real-World Noise for Listeners With Typical Hearing and Hearing Loss.

Purpose: This study is a preliminary exploration of frequency importance functions for sentence recognition in real-world noise in listeners with typical hearing and listeners with hearing loss in unaided and aided conditions.

Method: Participants with typical hearing (n = 25) and participants with sloping, high-frequency hearing loss (n = 17) repeated back target sentences presented in virtual acoustic scenes (church, cafe, dinner party, and food court) in a trial-by-trial design. Frequency-specific signal-to-noise ratios (SNRs) were calculated for each trial across 35 gammatone filters with center frequencies from 125 to 12000 Hz. Frequency importance was computed by regressing the proportion of keywords correct in each sentence against frequency-specific SNRs.

Results: Frequency importance functions differed across environments; however, important frequencies were generally mid-to-high frequency, with the most consistent peak of the importance function observed at 2334 Hz. Participants with typical hearing relied on a greater range of frequencies than those with hearing loss, with differences across groups most evident for high frequencies. Providing additional high-frequency audibility with amplification increased frequency importance.

Conclusions: Frequency importance functions are environment dependent and may differ based on the degree of informational or energetic masking in each environment. Frequency importance functions vary across listeners and hearing aid conditions, likely because of differences in audibility. Environmental and listener-specific frequency importance functions can inform hearing aid design and rehabilitation approaches.

Supplemental material: https://doi.org/10.23641/asha.30059296.