Effect of Aging on Middle Ear Absorbance Characteristics Across Frequencies.

Area of Science:

• Audiology
• Gerontology
• Otolaryngology

Background:

• Age-related hearing loss is common, but effects on middle ear mechanics are less understood.
• Wideband tympanometry (WBT) provides frequency-specific acoustic transfer function data, unlike conventional methods.
• Anatomical variations across ethnicities may influence middle ear acoustic transmission.

Purpose of the Study:

• To investigate the impact of aging on middle ear absorbance across a range of frequencies using WBT.
• To compare middle ear absorbance patterns between young and older adults with normal hearing.

Main Methods:

• A comparative study design involving 60 ears from young adults (20-30 years) and older adults (50-70 years).
• Wideband absorbance measurements were taken using click stimuli (0.2-8 kHz) under ambient and peak pressure conditions.
• Statistical analysis included mixed repeated-measures ANOVA and independent/paired t-tests to compare groups and conditions.

Main Results:

• Older adults demonstrated significantly higher absorbance at low frequencies (250-600 Hz) and lower absorbance at high frequencies (2000-8000 Hz) compared to young adults.
• Middle ear absorbance patterns were similar between groups, but age-related differences in magnitude were significant.
• Younger adults showed more pronounced pressure-related absorbance changes, indicating greater sensitivity to pressure variations at low-to-mid frequencies.

Conclusions:

• Wideband tympanometry (WBT) is a sensitive tool for detecting subtle age-related changes in middle ear mechanics.
• Findings suggest age-related ossicular joint loosening and tissue degeneration contribute to altered middle ear function.
• Results may inform hearing aid fitting strategies for older adults and indicate gender is not a significant factor in middle ear transfer function.