LM301 - Hearing Loss and Cognitive Decline: What Are the Hearing Aid Fitting Implications?

Abstract:
The latest Lancet Commission report on dementia prevention, intervention, and care was released in 2024. Similar to the first report, this report indicates untreated hearing loss is a modifiable risk factor for cognitive decline. The report reviews new findings including the loss of ability to hear in noise. SNR loss is associated with 1.91 greater odds of developing dementia. This session will focus on the latest literature with regard to hearing loss and cognition and how both the diagnostic evaluation and hearing aid fitting should change given these findings. There are additional considerations for hearing aid fitting and cognition.

Summary:
On July 31, 2024, the Lancet Commission on dementia prevention, intervention, and care released their latest report. This is the 2nd Lancet Commission report on this topic. The first report was released in Lancet in 2020. In the 2020 report, hearing loss was identified as a modifiable risk factor accounting for 7% of the variance. In total, 12 risk factors were identified in the 2020 report including untreated hearing loss, depression, social isolation, less education, obesity, hypertension, smoking, physical inactivity, diabetes, excessive alcohol consumption, traumatic brain injury, and air pollution. The 2024 report adds two more risk factors including high cholesterol and untreated visual loss. In all, the 14 factors in the 2024 report account for 45% of the variance. Theoretically, about half of all dementia cases could be prevented by eliminating these 14 risk factors. When hearing loss (7%) and two factors that can accompany hearing loss, depression (3%) and social isolation (5%), are combined, 14% of the modifiable risk could be accounted for. One new and interesting finding in the report related to hearing loss was about hearing in noise. The greater the loss of ability to hear in noise, the more likely to have dementia. SNR loss that was more than predicted by the hearing loss alone was associated with 1.91 greater odds of developing dementia.

This leads to some considerations in hearing aid fitting where hearing in noise is concerned. Care needs to be taken to consider the patient’s ability to hear in noise when selecting amplification and accessories like companion microphones. For example, accessories should be recommended when the hearing aid alone will not provide the needed benefit in noise. In addition, binaural beamformers should be recommended over two-microphone directionality when SNR losses are greater. The easiest way to ensure the patient’s hearing in noise ability is taken into consideration is to measure SNR loss as a standard part of the hearing evaluation. Knowing the patient's ability to hear in noise makes the recommendations to solve this issue more concrete.

This session will give an update on the latest literature with regard to hearing loss and cognition. These findings will then be addressed in terms of the diagnostic evaluation which should include some measure of SNR loss. Once this loss is known, the selection of what hearing aid to use will be addressed. Specific features that will be discussed are directionality including beamforming, noise reduction, time constants, and the use of more than one program. Clinicians will takeaway information that can be used with patients on their first day back to the clinic.

Brief Summary of Clinical Takeaways:
The clinical takeaway for this session is that measuring a patient's signal-to-noise ratio loss is imperative to selecting the best amplification and accessories to help mitigate future cognitive decline.