System for making quantitative, in vivo measurements of inner ear tissue impedances

An in vivo impedance measurement system capable of accurately and nondestructively measuring complex tissue impedances within a guinea pig cochlea is introduced. The measurement system is based on a four-electrode reflection coefficient technique, and the general technique can be readily applied to any tissue or aqueous system that can be theoretically modeled. Calibrations involving glass, which represents an ideal in vitro system, validate the accuracy of the proposed impedance measurement system