Symposium on sensorineural hearing loss in children: early detection and intervention. Impedance measurement.

Although impedance measurement is a relatively new procedure, at least in this country, it is rapidly being recognized as one of the most significant contributions since the development of the pure tone audiometer. With the basic applications of the procedure it is possible to determine not only the presence but also to a great extent the specific nature of middle ear impairment, even in patients for whom audiometric results are limited and uncertain. Further applications of impedance measurement include the determination of nonorganic hearing loss and site-of-lesion testing to distinguish between cochlear and retrocochlear lesions. Finally it appears that the procedure may even permit the prediction of severity and configuration of sensorineural loss. Although impedance measurement has great value in all patients with hearing disorders, it is particularly appropriate in pediatric evaluation. Its objectivity, its ease of application, and the information that can be obtained with it make impedance measurement a significant and valuable addition to the battery for evaluation of hearing disorders in children.