Peripheral hearing loss: implications for clinical dichotic listening tests

Area of Science:

• Audiology
• Neuroscience
• Speech and Hearing Sciences

Background:

• Dichotic listening tests are used to assess central auditory processing disorders.
• Peripheral hearing loss can potentially confound the interpretation of these tests.
• Understanding this interaction is vital for accurate diagnosis.

Purpose of the Study:

• To evaluate how unilateral conductive hearing loss affects dichotic listening test outcomes.
• To determine the impact of test intensity on dichotic performance in the presence of simulated hearing loss.

Main Methods:

• A normal-hearing listener was tested using CV nonsense syllables under monotic and dichotic conditions.
• A unilateral conductive hearing loss was simulated using an earplug in one ear.
• Testing was performed at various intensities, comparing plugged and unplugged conditions.

Main Results:

• Simulated hearing loss caused significant variations in the ear advantage with changing test intensity.
• These variations occurred even when monotic speech recognition scores remained above 95% in both ears.
• Test intensity significantly influenced the reliability of dichotic listening results.

Conclusions:

• Peripheral hearing loss can confound central auditory deficit assessments using dichotic listening tests.
• Recommend maintaining test intensity at least 10 dB from the performance-intensity function's knees for accurate results.
• This adjustment helps mitigate the confounding effects of peripheral hearing loss on dichotic test interpretation.