An alternate method for determining functional gain of hearing aids

Area of Science:

• Audiology and Hearing Science
• Biomedical Engineering

Background:

• Functional gain in hearing aids is traditionally measured by comparing aided and unaided behavioral thresholds.
• This conventional method can lead to underestimation of true gain in frequency regions with normal or near-normal hearing sensitivity, such as in sloping, rising, or trough-shaped audiograms.
• Internal hearing aid noise and amplified ambient noise limit the accuracy of obtainable aided thresholds.

Purpose of the Study:

• To evaluate the efficacy of comparing aided and unaided acoustic-reflex thresholds as a clinical alternative for determining real-ear gain.
• To compare sound-field behavioral threshold and acoustic-reflex threshold estimates of functional gain across diverse audiometric configurations.

Main Methods:

• Participants with various audiometric configurations were assessed.
• Functional gain was estimated using both sound-field behavioral thresholds and acoustic-reflex thresholds.
• Comparison of the two estimation methods was performed.

Main Results:

• Sound-field behavioral threshold measurements underestimated functional gain when unaided hearing thresholds were near the normal hearing range.
• Acoustic-reflex threshold measurements provided a more accurate estimation of functional gain in these specific cases.
• In regions of significant hearing loss, both behavioral and acoustic-reflex methods yielded comparable estimates of functional gain.

Conclusions:

• Acoustic-reflex thresholds represent a valuable clinical tool for accurately assessing hearing aid functional gain, particularly when behavioral thresholds may be unreliable.
• The findings suggest that incorporating acoustic-reflex measurements can improve the precision of hearing aid fitting and verification, especially for individuals with mild hearing impairments.