Post-auricular muscle reflex in the Middle Latency Evoked Auditory Response

Area of Science:

• Audiology
• Neuroscience
• Electrophysiology

Background:

• The Middle Latency Auditory Evoked Response (MLAER) is a key electrophysiological measure.
• The post-auricular muscle reflex can occur at similar latencies, potentially confounding MLAER interpretation.

Purpose of the Study:

• To investigate the influence of the post-auricular muscle reflex on MLAER.
• To determine the optimal electrode placement for accurate MLAER recording.

Main Methods:

• A prospective study involving 40 normal-hearing adults (18-40 years).
• MLAER was assessed with electrodes placed on mastoids and then earlobes.

Main Results:

• Significant differences in Na-Pa amplitude and wave latencies were observed between mastoid and earlobe placements.
• The post-auricular reflex occurred more frequently with mastoid electrode placement.

Conclusions:

• Post-auricular muscle reflex interferes with MLAER when electrodes are placed on the mastoid.
• Earlobe electrode placement is more efficient for accurate MLAER capture and registration.