THE BIOMECHANICS CHARACTERISTICS OF THE MIDDLE-EAR SYSTEM MEASURED BYA NEW METHOD .2. CLINICAL-APPLICATION AND NORMAL MATERIAL

An instrument for measuring the pressure-volume relationship of the mi ddle ear system was introduced earlier. This paper describes the pract ical application of the instrument and presents a normal material of 4 5 healthy young adults. Reflecting a slight increase in pressure in th e ear canal during the measuring procedure, a series of curves is obta ined, each representing a different position of the tympanic membrane. From these curves the zero curve is defined, representing the zero po sition of the drum. This curve is used to determine the variables of t he pressure-volume relationship of the middle ear system: hysteresis, pressure range, P-ec0, and compliance. The variables express objective and dynamic measures of the mechanical properties of the middle ear. The method had an acceptable repeatability and was found to be consist ent with earlier investigations. It is easy to perform and causes the subject no discomfort. It is therefore considered useful for further i nvestigation of middle ear physiology and pathophysiology.