PP316 - Aided and Unaided Neural Activity During Speech Perception in Noise

Abstract:
In the U.S., nearly half of adults over 75 suffer from disabling age-related hearing loss (ARHL). However, 78% of them do not utilize advanced hearing aid technology. The consequences of ARHL, such as increased dementia rates and decreased cognitive function, are alarming. Our study aimed to examine cognitive changes in ARHL patients by observing neurophysiological processes using functional Near Infrared Spectroscopy before and after hearing aid intervention. Preliminary findings from 9 participants show enhanced neuronal activity in the auditory cortex with hearing aid use during speech perception tasks. This suggests the potential benefits of hearing aids in cognitive function enhancement.

Summary:
Nearly 50% of adults over 75 years in the United States have disabling age-related hearing loss (ARHL). Yet, despite significant advances in hearing aid technology, a large percentage (78 %) of older adults with ARHL do not own and use hearing aids. ARHL is associated with a higher incidence of dementia, social isolation, decreased cognitive functioning, poorer physical functioning, and reduced quality of life (Bucholc et al., 2022, Lin 2023). Given the high prevalence of ARHL and increased rates of cognitive decline in the elderly population, the overall aim of our study is to assess the behavioral and neurophysiological changes in the cognitive functioning of individuals with ARHL before and after intervention with hearing aids.  Participants were assessed with a sensitive neurocognitive battery and functional Near Infrared Spectroscopy is a non-invasive neuroimaging technique that uses near-infrared light to monitor and measure brain activity. For this presentation, we focus on analyzing and reporting the neurophysiological processes evident in the temporal lobe during speech perception in noise tasks delivered at the baseline. To date, fNIRS data have been collected and analyzed on 9 adults with a mean age of 82.4 (we hope to have data on 12 participants before the conference). All participants have bilateral Sensorineural hearing loss with speech frequency pure tone average (1000, 2000, and 4000 Hz) of > 40 dB HL and have never worn hearing aids.

After the initial audiological evaluation, hearing aids were programmed for individuals' hearing loss using NAl-NL2 prescriptive formula and verified using real ear measurements. Two hearing aids (Oticon More 1 and Signia Charge and Go 7AX) were used for the study and programmed uniformly by activating one universal program with a 6 dB volume control. We used fNIRS (Hitachi ETG-4000) to monitor changes in oxygenated hemoglobin concentration values in individuals with and without hearing aids. Participants were presented with Quick SIN sentences amidst multi-talker babble at a consistent intensity of 70 dB SPL both in quiet and noisy backgrounds. Data was captured using two 3x5 probe sets, together containing 44 channels, specifically targeting the frontal lobes and left temporal lobes. Beta values were constructed by solving a generalized linear model for every channel for each subject. Group activation results revealed a significant increase in oxygenated hemoglobin concentration within the auditory cortex when participants used their hearing aids during both quiet and noisy background conditions in contrast to the conditions without hearing aids. Our findings suggest that hearing aid use is associated with increased neuronal activity in the auditory cortex during speech perception and may be a viable tool in enhancing cognitive functioning in an aging population. 

This research is funded by Alzheimer’s Disease and Dementia Research Center at USU and Hearing aids are sponsored by Oticon and Signia (https://www.signia.net).