The Displacement of the Stapes by the Reflex of the Human Stapedius Muscle

Abstract

The integral characteristic of the human stapedius muscle is recorded. The sound stimulus is applied to the contra-lateral ear. Changes in the contractile state of the stapedius muscle, as measured by the displacement of the head of the stapes according to the sound-frequency and the intensity, and the adaptation of the muscle by successive stimuli for two min at 2000 cps and 120 dB SL are measured.

It is well known that an acoustic or non-acoustic stimulus induces the reflex contraction of the stapedius of both ears. Electromyography as a method of studying the properties of muscle is a differential method and lacks the ability to evaluate completely the properties of muscle adequately (Fisch & Schulthess, 1963; Djupesland, 1965). To date, however, there has been no report concerning an integral and quantitative method of measuring the changes of the human stapedius muscle.