The significance of negative middle ear pressure.

An increasing body of experience is defining the value of the impedance bridge for the detection and diagnosis of otologic disorders. In this study the audiometric status of 1,133 ears is correlated with the tympanometric configuration and middle ear pressure. It is noted that the air-bone gap systematically increases as the middle ear pressure decreases from 0 to -400 mm Ho. Mildly negative middle ear pressure (Jerger's Type A Tympanogram) produces air-bone gaps statistically greater than at atmospheric pressure. These data demonstrate the magnitude of the adverse effect of negative middle ear pressure upon middle ear auditory function.