Measurement of Dynamic Frequency Characteristics of Guinea Pig Middle Ear by a Laser Doppler Velocimeter

Abstract

The objective of the present study is to clarify the dynamic behavior of the middle ear by measuring the middle ear vibration directly. The velocity amplitudes of the tympanic membrane and ossicles of guinea pigs are measured before and after the manipulation of the cochlea and bulla using a laser Doppler velocimeter coupled to a compound microscope. The frequency characteristics of the middle ear vibration after the manipulation are different from those before it. These differences are explained by considering mass and damping components of the cochlear impedance and mass and stiffness components of the bulla's impedance.