On the dynamics of the preference-performance relation for hearing aid noise reduction

Previous research has shown that hearing aid users can differ substantially in their preference for noise reduction (NR) strength, and that preference for and speech recognition with NR processing typically are not correlated (e.g. Neher 2014; Serman et al. 2016). In other words: hearing aid users may prefer a certain NR setting, but perform better with a different one.
The aim of the present work was to investigate the influence of individual noise sensitivity, hearing aid experience and acclimatization on the preference-performance relation for different NR settings. For this purpose, a longitudinal study with three consecutive laboratory assessments distributed over a 12-week period was conducted. Two experimental groups of experienced and inexperienced hearing aid users (N = 20 each) participated. These subjects were bilaterally fitted with hearing aids (HA) with individual NAL-NL1-based hearing loss compensation (HL). All adaptive HA parameters were set to the default values in the fitting software. A control group of experienced hearing aid users (N = 10) completed the study with their own HAs.
All participants were selected based on their preferred NR strength as assessed during an initial screening visit (N = 100). Care was taken to ensure that the groups were comparable in terms of age and hearing loss, and that there were notable differences in preferred NR strength (“NR haters” vs. “NR lovers”) within each experimental group.
The laboratory assessments of preference and performance were conducted with four different NR settings: (1) only HL compensation, no further signal processing, (2) HL compensation and single-channel NR, (3) HL compensation and directional microphones (DIR), and (4) HL compensation combined with DIR and NR. Preference was assessed with a spatial dynamic speech-in-noise task after Getzmann et al. (2015) that required the participants to attend to a target speaker while ignoring simultaneously occurring distractor talkers. In addition, speech understanding and recall was assessed using a listening span test (Fischer et al. 2017).
Here, we report on the data collected during the first laboratory assessment of the study. In particular, the influence of hearing aid experience and individual noise sensitivity on the preference-performance relation will be presented and discussed.