The Challenge of Capturing Hearing Aid Benefit: Interindividual Differences in Response to Changes in Signal Processing.

Purpose: The benefits of digital signal-processing features, such as noise reduction (NR) and frequency compression (FC), differ among individuals. This study aimed to explore the impact of deactivating NR and FC on hearing aid (HA) benefit, acknowledging the complexity of interindividual variability. Method: Thirty-two first-time HA users were assigned to three groups: a control group with no feature changes (n = 10, mean age [MA] = 68.40 years), an NRoff group (n = 11, MA = 65.82 years), and an FC-off group (n = 11, MA = 66.82 years). Two test sessions were separated by about 4 weeks of acclimatization. Session 1 included baseline assessments (cognition, speech understanding, subjective measures) using initial HA settings, followed by immediate speech understanding reassessment after group allocation. In Session 2, speech understanding and subjective outcomes were reassessed. Wilcoxon signed-ranks and Kruskal--Wallis tests examined within-group and betweengroups differences. Results: No significant effects of NR or FC on speech understanding or subjective measures were observed, but small trends emerged. Subjective improvements were most consistent in the control group. Tentative minor trends in subjective ratings suggested FC deactivation may be associated with declines in auditory--visual and psychosocial functioning and improvements in cognitive functioning, listening effort, and fatigue. Conclusions: Exploratory patterns suggest FC may impact subjective outcomes differently, despite no significant effects being found. The findings further critically reflect the complexity of evaluating cognition-related HA benefit and emphasize the need for multidimensional research to guide individualized HA fitting. Supplemental Material: https://doi.org/10.23641/asha.31141591 [ABSTRACT FROM AUTHOR]