Older listeners' use of temporal cues altered by compression amplification

Area of Science:

• Audiology
• Speech Perception
• Gerontology

Background:

• Speech comprehension relies on processing temporal and spectral information.
• Hearing aid amplification, particularly wide-dynamic range compression (WDRC), can alter speech cues.
• Age and hearing loss can impact the ability to perceive altered speech signals.

Purpose of the Study:

• To compare how younger and older adults, with and without hearing loss, utilize temporal information in speech modified by compression amplification.
• To investigate the effects of WDRC and linear amplification on speech recognition, focusing on temporal and spectral cues.
• To determine if age-related deficits in temporal resolution are exacerbated by WDRC amplification.

Main Methods:

• Speech recognition of vowel-consonant-vowel syllables was tested in four listener groups (young/old, normal/impaired hearing).
• Syllables were processed using WDRC and linear amplification, with and without spectral information, presented with a high-frequency masker.
• Performance was assessed under conditions isolating temporal information versus combined temporal and spectral information.

Main Results:

• WDRC-amplified speech yielded lower recognition scores than linearly amplified speech across all groups.
• Older listeners generally performed worse than younger listeners.
• The age-related decline in speech recognition was more pronounced for WDRC-amplified speech when spectral information was restricted in normal-hearing listeners.

Conclusions:

• Older adults can effectively use WDRC hearing aids when spectral cues are available and they have adequate spectral resolution.
• For older adults without hearing loss, poorer performance with compression-amplified speech indicates an age-related deficit in temporal resolution.
• These findings have clinical implications for fitting hearing aids to older individuals, particularly concerning the impact of compression on temporal processing.