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Updated: Jul 17, 2026
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Infant Auditory Processing and Event-related Brain Oscillations
Published on: July 1, 2015
Age-related differences in neuromagnetic brain activity underlying concurrent sound perception
Claude Alain1, Kelly L McDonald
1Rotman Research Institute, Baycrest Centre for Care, Toronto, Ontario, Canada M6A 2E1. calain@rotman-baycrest.on.ca
Summary
Aging impairs the brain's ability to distinguish simultaneous sounds, affecting speech comprehension in noisy environments. This study reveals age-related declines in auditory processing, impacting sound segregation perception.
Area of Science:
- Auditory Neuroscience
- Gerontology
- Speech Perception
Background:
- Older adults often struggle with understanding speech in noisy settings like cocktail parties.
- Deficits in processing concurrent auditory events are a key factor in age-related hearing difficulties.
Purpose of the Study:
- To investigate how aging affects the brain's ability to segregate simultaneous sounds.
- To examine age-related differences in auditory cortical activity in response to mistuned harmonic complexes.
Main Methods:
- Magnetoencephalography (MEG) was used to measure auditory evoked fields (AEFs) in young, middle-aged, and older adults.
- Participants listened to sounds with in-tune or mistuned harmonics while watching a muted movie.
- AEFs were modeled using dipole sources in the superior temporal plane to analyze age and mistuning effects.
Main Results:
- Mistuned sounds elicited early brain responses (60-230 ms) similarly across all age groups.
- Older adults showed reduced later auditory cortical responses (object-related negativity and P230) to mistuning.
- Age-related reductions in these responses correlated with a decreased ability to perceive concurrent sounds.
Conclusions:
- The brain rapidly and automatically detects inharmonicity regardless of age.
- Perception of concurrent sounds, crucial for speech understanding in noise, declines with age due to reduced auditory cortical processing.
- These findings highlight age-related changes in auditory segregation impacting real-world listening.
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