Acoustic and Perceptual Effects of WDRC Amplification

The goal of personalized medicine is to improve treatment efficacy by basing that treatment on individual abilities and characteristics. There is an acute need for such treatment approaches in hearing health care, where hearing aids (the primary treatment for hearing loss) have had limited acceptance and uncertain individual benefits. Here, we apply the principal of personalized treatment to select signal processing that is customized to individual auditory profiles. The aims below build on our previous work and transition that work to clinical practice. This project encompasses three sets of experiments that take a systematic approach to prescribing amplification parameters, and move forward from our previous work in this area. The first specific aim is to demonstrate how different cue use patterns affect response to hearing aid signal processing in quiet and in adverse listening environments. We will combine acoustic analysis from a modulation-based acoustic model with behavioral measurements to understand the relationship between reverberation and the changes in the modulation domain that are imposed by amplification signal processing. We will also measure the extent to which the listener’s dependence on specific speech cues increases susceptibility to processing. The second specific aim is to expand our understanding of the listener profiles which influence the outcome of signal-processing amplification. For listeners with a wide variety of hearing loss etiology and audiometric configurations, we will measure specific aspects of auditory processing that are likely to be related to listener profile. We hypothesize that while all listeners will demonstrate cue profiles that are not well predicted by their audiograms, listeners with severe hearing loss will be more likely to rely on temporal cues to speech. We also hypothesize that listeners with poorer spectral resolution will demonstrate reliance on temporal speech cues. We anticipate the outcome of this aim will support a novel “listener profile” test which can be adapted for clinical use in selecting hearing aid signal processing. The third specific aim is to demonstrate the consequences of profile-directed signal processing for speech perception in everyday listening. This aim will employ wearable hearing aids and realistic listening environments. Simulated reverberant and noisy environments will be created in Northwestern’s Virtual Sound Room. We will also undertake a brief clinical trial to assess listener’s subjective response to profile-directed fittings in their daily life. We hypothesize that the relationships demonstrated in Aim 1 will be present in everyday environments. Taken together, the questions addressed in this project will provide a comprehensive assessment of the effects of hearing aid processing in realistic listening environments, while considering patient-specific abilities that affect response to signal processing.