Ipsilateral acoustic reflex artefacts measured in cadavers

Area of Science:

• Audiology
• Biomedical Engineering
• Otoacoustic Emissions

Background:

• Impedance audiometry is crucial for assessing middle ear function.
• Acoustic reflexes are commonly measured using impedance meters.
• Artifacts can compromise the accuracy of impedance measurements.

Purpose of the Study:

• To determine the minimum stimulus levels causing artifactual impedance changes in cadaver ears.
• To evaluate the effectiveness of different impedance meter designs in minimizing artifacts.
• To investigate methods for increasing artifact thresholds.

Main Methods:

• Six impedance meters were used to present acoustic stimuli to cadaver ears.
• Stimulus levels and frequencies were varied to detect impedance changes.
• Pressure differentials across the tympanic membrane were manipulated.

Main Results:

• Artifactual impedance changes were detected in five of six instruments across tested frequencies.
• One instrument using a pulsed stimulus technique exhibited significantly fewer artifacts.
• Introducing pressure differentials yielded only minor increases in artifact thresholds for most devices.

Conclusions:

• Most conventional impedance meters are susceptible to generating artifacts during acoustic reflex testing.
• Pulsed stimulus techniques show promise in reducing measurement artifacts.
• Further research is needed to optimize impedance measurement techniques and minimize artifacts in audiological assessments.