Hearing aid noise reduction function for tonal language perception

Abstract

Purpose: This study aimed to evaluate the efficacy of hearing aid noise reduction for Mandarin speakers. Method: The acceptable noise level (ANL) test and Mandarin Hearing in Noise Test (MHINT) were measured in three noise reduction (NR) conditions (NR off, NR 10, NR 20). Self-report sound quality rating was measured under four NR conditions to evaluate listening effort, listening comfort, speech clarity and overall quality. 32 Mandarin-speaking listeners with moderate and severe hearing loss and who had used hearing aids for at least 3 months participated the study. Results: Great inter-subject variability in results was observed with all tests. Repeated measures ANOVA showed significant main effects of noise reduction conditions, post hoc tests showed significant differences between all settings. For MHINT test, repeated measures ANOVA revealed significant effects of noise reduction conditions, post hoc tests showed significantly better SRT with the NR conditions than without NR. MHINT and ANL results obtained for each noise reduction conditions did not correlate, except that there was low degree of correlation under the setting NR 20. Overall, most listeners preferred some noise reduction than no noise reduction, but aggressive NR was less preferred. Conclusion: The findings indicated that listeners had a higher tolerance for noise with noise reduction setting on, particularly at a more aggressive noise reduction setting. Listeners had better speech recognition and with noise reduction setting on, speech recognition did not improve with more aggressive noise reduction (NR 20). Listeners’ ability to tolerate noise was not related to their speech recognition ability except for a low correlation at NR20. For self-report sound quality, listeners basically prefer some noise reduction for listening comfort, speech clarity, listening effort and overall quality but NR 20 was less preferred.