Sensorineural hearing loss enhances auditory sensitivity and temporal integration for amplitude modulation.
Nicolas Wallaert1, Brian C J Moore2, Stephan D Ewert3
1UMR CNRS LSP 8248, Institut d'Etude de la Cognition, Ecole normale supérieure, Paris Sciences et Lettres Research University, 29 rue d'Ulm, 75005 Paris, France.
The Journal of the Acoustical Society of America
|March 4, 2017
Summary
Hearing-impaired listeners show enhanced sensitivity to amplitude modulation (AM) detection, with greater improvements at lower modulation rates. This suggests cochlear damage impacts temporal processing and AM detection.
Area of Science:
- Auditory Neuroscience
- Psychoacoustics
- Signal Processing
Background:
- Sensorineural hearing loss (SNHL) affects auditory processing, particularly temporal aspects.
- Amplitude modulation (AM) detection is crucial for speech intelligibility.
- Previous research established AM detection thresholds (AMDTs) in normal-hearing listeners.
Purpose of the Study:
- To measure AMDTs in individuals with mild-to-moderate SNHL.
- To compare AMDTs in hearing-impaired listeners with those of normal-hearing listeners.
- To investigate the influence of modulation rate and number of cycles on AMDTs in SNHL.
Main Methods:
- AMDTs were measured at 40 dB sensation level for a 500 Hz carrier frequency.
- Modulation rates of 2 Hz and 20 Hz were used, with the number of modulation cycles (N) varying from 2 to 9.
- Data were compared to previously published data from normal-hearing listeners.
Main Results:
- AMDTs were lower for hearing-impaired listeners compared to normal-hearing listeners.
- AMDTs decreased with increasing number of modulation cycles (N) for both groups.
- The effect of increasing N was more pronounced in hearing-impaired listeners.
- A computational model simulating AM detection was developed.
Conclusions:
- Loss of cochlear amplitude compression contributes to enhanced temporal envelope cue processing in SNHL.
- Cochlear damage in SNHL is associated with increased internal noise but preserved short-term memory and decision mechanisms for AM detection.
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