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Age-related reduction of amplitude modulation frequency selectivity
Jonathan Regev1, Johannes Zaar2, Helia Relaño-Iborra1
1Hearing Systems Section, Department of Health Technology, Technical University of Denmark, Kongens Lyngby, 2800, Denmark.
The Journal of the Acoustical Society of America
|April 24, 2023
Summary
Older adults show reduced frequency selectivity in amplitude modulation (AM) processing, impacting complex sound perception. This age-related decline in AM processing persists even with similar basic detection abilities.
Area of Science:
- Auditory Neuroscience
- Psychoacoustics
- Human Auditory Perception
Background:
- Amplitude modulation (AM) perception relies on frequency-selective processing in the temporal envelope.
- This process is crucial for understanding complex sounds, including speech.
- Age-related changes in auditory processing are well-documented, but their specific impact on AM selectivity requires further investigation.
Purpose of the Study:
- To investigate the effects of aging on behavioral AM frequency selectivity in listeners with normal hearing.
- To compare AM frequency selectivity between young and older adult groups.
Main Methods:
- A simultaneous AM masking paradigm was employed.
- Stimuli included a 2.8 kHz sinusoidal carrier with target modulation frequencies of 4, 16, 64, and 128 Hz.
- Narrowband-noise modulation maskers were used to assess frequency selectivity.
Main Results:
- Older listeners (57-77 years) exhibited reduced AM frequency selectivity compared to young listeners (22-29 years), with selectivity reduced by up to a factor of two.
- AM selectivity correlated with unmasked AM detection sensitivity.
- Age-related broadening of masked threshold patterns was observed, even when AM sensitivity was comparable across age groups with extended stimulus duration.
Conclusions:
- Aging significantly impacts AM frequency selectivity in the auditory system.
- Reduced AM selectivity in older adults may have implications for complex sound perception.
- Further research is warranted to explore the interplay of age, hearing impairment, and AM processing.
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