Hearing aids have specialized features to improve access to sounds for the hearing-impaired listener. The choice of appropriate hearing aid settings is integral to the hearing rehabilitative process. Researchers and clinicians have been influenced by previous work showing that individual cognitive abilities, including working memory are associated with hearing aid benefit, especially in adverse listening conditions. However, previous research is limited to omnidirectional microphone settings and unrealistic listening conditions. Such conditions fail to recognize that most hearing aids are fit with directional processing that may improve the listening environment, and that typical environments contain speech and noise signals in a range of spatial locations. Therefore, the broad goal of this research is to understand how patient variables interact with hearing aid signal processing in realistic listening conditions in order to effectively treat hearing-impaired individuals in communications situations that are most important to them. The proposed work is in alignment with NIDCD's mission to conduct and support behavioral research and research training in interventions (i.e. hearing aids) that substitute for lost/impaired sensory and communication function (i.e., hearing loss).
The specific aims examine the relationship between working memory and hearing aid signal processing (WDRC in the presence of microphone directionality) in spatial conditions ideal for directionality (Aim 1) and realistic spatial conditions (Aim 2). In a clinical trial, hearing-impaired listeners will use wearable hearing aids with different hearing aid processing settings (WDRC speeds, microphone directionality patterns and technology) and identify speech in different listening conditions (spatially varying speech and noise). Performance across conditions will be related to listeners' auditory abilities and working memory capacities using a mixed design. Existing acoustic metrics will be used to associate individual outcomes to overall signal fidelity across conditions. The K01 award will enable the PI to build upon her existing research and clinical experience with hearing aids and provide structured training in the following areas: a) focused research on the impact of microphone directionality on individual hearing aid outcomes in realistic spatial conditions, b) designing a clinical trial with wearable hearing aids, and c) advancing scientific communication skills. Research and training experience through this award will help the PI achieve her long-term goal of performing rigorous independent research in the individualized care of hearing-impaired adults. The proposed work will take place at Northwestern University under the mentorship of Dr. Pamela Souza and Dr. Richard Freyman.
An influential body of research shows that cognitive variables should be considered in the selection of hearing aid settings. However, evidence in the context of clinically-relevant hearing aid settings and realistic spatial conditions is lacking. The long-term goal of this work is to help prescribe appropriate hearing aid settings for individual hearing-impaired listeners so that they can experience successful communication in everyday listening situations.