Evaluation of Tensor tympani Muscle Dominance in the Biphasic Acoustic Reflex

Abstract

The Acoustic reflex frequently causes a biphasic change in impedance at onset. Understanding the cause of the biphasic response is important for establishing a physiological basis for the clinical measurement of reflex latency. The decrease in impedance at onset may be due to uncoupling of impedance contributed by the cochlea. Subsequent increases in impedance predominately reflect stapedius muscle activity. The clinical implications of this physiologic model are discussed.

Key Words:

• Acoustic reflex
• Stapedius muscle
• Tensor tympani muscle
• Facial nerve
• Acoustic impedance
• Acoustic reflex latency
• Monkeys