[Device for measuring the acoustic impedance of the middle ear].

There exists a direct proportional relation between the acoustic impedance of the tympanic membrane and static pressure in the external acoustic duct. This relation forms the basis of the UM-01 device which enables the acoustic impedance to be determined and allows it to judge from its magnitude on the condition of the sound-conducting sector of the auditory analyser. The device is simple to handle and does not require any balancing of the measuring portion in the circuit.