PP1021 - Relationship Between Auditory Measures and Cognitive Performance in Individuals with Age-Related Hearing Loss and Those with Normal Hearing

Abstract:
Many studies have examined the relationship between hearing and cognitive performance but have relied on subjective or non-speech auditory measures, leading to mixed results. This study obtained cognitive and auditory-based physiological and speech measures from participants with age-related hearing loss and those with normal hearing. Results indicated no significant differences between the two groups. However, when data were combined from both groups, cognitive and dichotic digit test scores showed a significant negative correlation with ABR peak V amplitude difference for high versus low stimulus rates, indicating a potential link that could better explain the relationship between auditory and cognitive measures.

Summary:
Objective
The objective of this study was to obtain cross-sectional data using behavioral, physiological, and speech-based auditory measures, along with cognitive measures, to better understand the relationship between hearing and cognitive performance. Our long-term goal is to use these findings in longitudinal investigations to assess the impact of age-related hearing loss (ARHL) on cognitive function and determine if hearing aids can preserve cognitive performance in individuals with ARHL.

Rationale
A decline in cognitive abilities is the hallmark of dementia, for which there is currently no cure. However, the Lancet Commission reports on dementia prevention have suggested that addressing 14 modifiable risk factors can potentially prevent or delay up to half of dementia cases, with hearing loss being the most potentially modifiable risk factor (Livingston et al., 2020, 2024). Several earlier studies that addressed this issue employed subjective or non-speech-based auditory test measures and found results ranging from no associations to strong associations (Cantuaria et al., 2024). Given these mixed findings, it is still uncertain whether subjective auditory assessments adequately assess the role of hearing and hearing loss intervention in cognitive decline. In this study, we postulated that by using physiological and speech-based auditory tests, we can objectively assess the relationship between hearing and cognitive performance.

Design
We included 24 participants, 14 with untreated ARHL (Group 1) and 10 with normal hearing (Group 2, control) between the ages of 55-75 years. The Montreal Cognitive Assessment-Hearing Impaired (MoCA-HI) version was used for cognitive screening. The auditory test battery included self-assessment questionnaires, pure tone audiometry, speech-based auditory tests [(Quick Speech in Noise test and Dichotic Digit Test ( DDT)], and Auditory Brainstem Responses (ABR) to low versus high stimulus rates.

We hypothesized that: (1) There will be a significant correlation between ABR, speech-based auditory, and MoCA-HI test scores, and (2) Groups 1 and 2 will significantly differ in auditory and MoCA-HI test scores.

Statistical Analyses
Pearson correlation coefficient was used to assess the relationship between auditory and cognitive test scores, and a mixed design ANOVA was used to assess the effects of group, time, and their interaction.

Results
1. Right ear ABR peak V amplitude difference for high versus low stimulus rates was negatively correlated with MoCA-HI and DDT scores.
2. No significant differences were found between Groups 1 and 2.

Conclusions
The two groups did not show significant differences in ABR measures, speech-based auditory tests, or MoCA-HI scores. However, when data were combined from both groups, higher DDT and MoCA-HI scores were associated with a smaller reduction in right ear ABR peak V amplitude at high stimulus rates. This suggested a more resilient right ear response under stressful conditions among participants with better speech perception and higher MoCA-HI scores.

Future goals
These findings will guide our next study, which aims to divide ARHL participants into treated (hearing aid intervention) and untreated groups and obtain longitudinal data. Obtaining objective evidence is crucial for understanding the relationship between hearing loss, hearing aid use, and cognitive decline, ultimately helping to reduce the risk of dementia.