Hearing loss is among the top three major health conditions in older adults and has been identified as a major modifiable risk factor for dementia. It is therefore imperative that older adults receive effective treatment for hearing loss in a timely manner to prevent losses in social, emotional, and cognitive function. The current hearing aid fitting is based on audiometric thresholds, but this approach does not account for large individual differences in auditory temporal perception and cognitive ability that may affect speech understanding in challenging listening environments. At present, there is a gap in knowledge of how best to fit hearing aids for individual listeners. The long-term goal is to improve the benefit of hearing aids for older adults so that they can maintain independence and quality of life. The overall objective of this proposal is to identify the neural temporal processing mechanisms associated with individual differences in hearing aid benefit in older adults with similar audiograms. The investigators will use the innovative approach of combining complementary neural and behavioral measures to assess the effects of hearing aid amplification on speech perception and effortful listening. The central hypothesis is that the neural representation of the temporal envelope of speech can be used to predict hearing aid benefit in older adults with hearing loss. The central hypothesis will be tested through the pursuit of three aims: (1) Measure the extent to which amplification distorts the neural and perceptual processing of temporal cues; (2) Quantify reductions in temporal envelope tracking and increases in cognitive effort associated with amplification algorithms that distort the temporal envelope of the speech signal; and (3) Investigate the use of objective physiological measures of temporal processing to predict hearing aid benefit. The expected outcome is the development of an objective, neurophysiological tool for use in the design and fitting of advanced algorithms to maximize speech perception in a variety of listening environments. This outcome is expected to have a positive impact on the treatment of hearing loss and its sequelae in older adults, because it will lead to a better understanding of the neural mechanisms contributing to successful use of hearing aids.
Hearing loss is a critical health concern in the rapidly aging population, affecting approximately 22 million older individuals in the United States. Yet, only 30% of individuals who would benefit from the use of hearing aids regularly use them. This project aims to improve the benefit of hearing aids for older adults through incorporation of objective neural measures to assess effects of hearing aid algorithms.