Multifrequency tympanometry and evoked otoacoustic emissions in neonates during the first 24 hours of life

Multifrequency, complex-component tympanograms and transient evoked otoacoustic emissions (EOAEs) were recorded in 55 neonates less than 24 hours of age. The purpose of the investigation was to determine the normal middle ear immittance characteristics of neonates less than 24 hours old (the approximate discharge age of well-babies) and to assess whether an association exists between transient EOAE response and middle ear status in neonatal ears. The tympanometric patterns recorded in the 55 neonates were, in general, not typical of those observed in older children and adults. Complex patterns were recorded at low probe frequencies indicating differences in the contribution of mass, stiffness, and resistance elements to admittance in the neonatal middle ear. Results from EOAE screening indicated a pass rate or partial pass rate of 82 percent. Although no clear association emerged between admittance characteristics and EOAE results, some interesting tendencies were noted.