Age-related changes in auditory temporal processing assessed using forward masking

• Published in: Hearing research 2023-01, Vol.427, p.108665, Article 108665
• Main Authors: Heidari, Parisa, Mohammadkhani, Ghassem, Bayat, Arash, Rouhbakhsh, Nematollah, Moore, Brian C.J.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aging; Auditory Perception; Auditory Threshold; Female; Forward masking; Hearing; Humans; Middle Aged; Noise - adverse effects; Perceptual Masking; Temporal processing; Time Perception
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/j.heares.2022.108665

•The rate of recovery from forward masking was compared for young and older adults.•All participants had audiometric thresholds within the normal range.•The signal level was fixed at 15 dB SL and the masker level was varied to determine the threshold.•The masker-to-signal ratios at threshold were higher for the young than for the older participants.•The rate of recovery from forward making was slower for the older participants than for young participants. One of the main complaints of older adults is difficulty understanding speech in noise. For older adults with audiometric thresholds within the normal range this difficulty may partly reflect deficits in temporal processing. The purpose of this study was to evaluate the effect of age on the rate of recovery from forward masking. There were seven young participants (four females; mean age 26 years) and seven older participants (six females; mean age 62 years) with normal audiometric thresholds, designated YNH and ONH groups. Signal frequencies of 500, 1000, 2000, and 4000 Hz were used. The level of the 20-ms signal was fixed at 15 dB SL for each participant and frequency. The 200-ms masker was a band of noise centered at the signal frequency with a bandwidth equal to the center frequency. The masker level was varied to determine the masker-to-signal ratio (MSR) required for threshold for masker-signal intervals (MSIs) of 5, 10, 20, 30, and 50 ms. The MSRs were smaller for the ONH group than for the YNH group, perhaps indicating lower processing efficiency for the former. Importantly, there was a significant interaction between MSI and the group. The change in MSR with increasing MSI was greater for the YNH than for the ONH group, indicating poorer temporal resolution for the latter.