Speech-in-Noise Ability and Longitudinal Cortical Thinning in Speech-Processing Networks

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Gerontology

Background:

• Age-related hearing loss is a significant risk factor for dementia.
• Neural mechanisms linking auditory dysfunction to cognitive decline are not fully understood.
• The predictive value of peripheral hearing loss, central auditory processing, and hearing aid use on neurodegeneration is unclear.

Purpose of the Study:

• To investigate the association between hearing thresholds, speech-in-noise ability, hearing aid use, and longitudinal cortical atrophy in older adults.
• To determine if auditory function predicts brain aging and cognitive trajectories.

Main Methods:

• Longitudinal cohort study with 3-year follow-up.
• Participants: 312 cognitively normal older adults (mean age 73.5 years).
• Assessments included structural MRI for cortical thickness, audiometry, speech-in-noise tests, and cognitive assessments.

Main Results:

• Poorer speech-in-noise performance was linked to faster cortical thinning in specific brain regions (inferior parietal, precuneus, middle temporal cortex, superior temporal sulcus).
• These associations were independent of peripheral hearing thresholds and hearing aid use.
• No significant link was found between hearing loss/hearing aid use and neurostructural changes or cognitive decline.

Conclusions:

• Central auditory processing impairment, specifically in speech-in-noise tasks, is associated with accelerated cortical thinning in speech-processing networks.
• Speech-in-noise ability may serve as an early marker of neural vulnerability.
• Peripheral hearing loss and hearing aid use did not predict neurostructural changes in this cohort.