Impedance Audiometry With Neonates

Abstract

This study was undertaken to obtain information regarding results of impedance audiometry of newborns. Forty normal babies varying from 36 to 151 hours old were tested with an electro-impedance bridge. The basic components of impedance audiometry were carried out. Approximately one half of the babies were retested for estimating reliability of the measures. Hermetic seals were obtained on every infant selected for testing. Results of compliance measurements indicated a median of 1.1 cu cm with a range from 0.54 to 1.75 cu cm. Tympanograms were identical to those obtained in normal ears of older patients, except that seven of the infants yielded two distinct peaks near zero air pressure. The stapedial reflex response was usually "masked out" by a generalized body movement although it was usually possible to observe a stapedial reflex in the absence of a behavioral response.