Age-related hearing loss represents a significant modifiable risk factor for dementia globally. Understanding the speech-in-noise ability of older adults may offer a critical window into their brain health. A recent longitudinal study published in JAMA Otolaryngology suggests that central auditory processing deficits are more indicative of neurodegenerative changes than peripheral hearing loss alone.

In a cohort of 312 cognitively normal older adults, researchers examined the relationship between hearing metrics and brain structure over three years. Consequently, they found that individuals with poor baseline speech-in-noise ability experienced accelerated cortical thinning. This atrophy was specifically observed in the inferior parietal cortex, precuneus, and superior temporal sulcus regions. Importantly, these findings highlight a link between central processing and brain structure that remains independent of simple sound detection.

Importance of Speech-in-noise Ability in Clinical Practice

Interestingly, the study noted that these brain changes occurred regardless of peripheral hearing thresholds. Furthermore, the use of hearing aids did not significantly alter the trajectory of cortical thinning in this group. Therefore, speech-in-noise ability may serve as an early behavioral marker of neural vulnerability. This marker often precedes the clinical onset of measurable cognitive decline. Clinicians should consider that central auditory processing might be a unique indicator of neurostructural aging.

These findings emphasize the need for comprehensive auditory assessments in geriatric care. While standard audiometry measures sound detection, it does not fully capture central processing capabilities. However, incorporating speech-in-noise tests could help clinicians identify patients at risk for faster neurodegeneration. This approach allows for earlier intervention and better monitoring of cognitive health in an aging population. Focusing on central mechanisms provides a clearer picture of auditory and cognitive intersection.

Frequently Asked Questions

What does speech-in-noise ability measure?

It assesses central auditory processing, which is the brain's ability to filter and interpret speech in complex acoustic environments. This differs from peripheral hearing, which focuses on the ear's ability to detect sound at different frequencies.

Can hearing aids stop cortical thinning?

In this specific longitudinal study, hearing aid use was not significantly associated with reduced rates of cortical atrophy over three years. However, hearing aids remain essential for improving communication and reducing social isolation, which are also linked to cognitive health.

Why is cortical thinning in the precuneus significant?

The precuneus is a region often vulnerable to early Alzheimer's disease pathology. The association between speech-in-noise deficits and thinning in this area suggests that auditory central processing may be tied to broader neurodegenerative processes.

Disclaimer: This content is for informational and educational purposes only. It does not constitute professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

Zanin J et al. Speech-in-Noise Ability and Longitudinal Cortical Thinning in Speech-Processing Networks. JAMA Otolaryngol Head Neck Surg. 2026 May 28. doi: 10.1001/jamaoto.2026.1050. PMID: 42207546.

Livingston G et al. Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. Lancet. 2020;396(10248):413-446.