High frequency tympanometry in neonates with normal otoacoustic emissions: measurements and interpretations.

Tympanometry is used in evaluating middle ear functional conditions. Before 6 months of age its results may be misleading. High-frequency studies aim to provide more valid procedures. In this study, 236 healthy newborns (127 male, 109 female; 73 % rural, 27 % urban) with age between 0 and 42 days (mean 27 days) no risk for hearing impairment; were analyzed for DPOAE. 209 babies who passed DPOAE were further analyzed for high-frequency tympanometry using Interacoustic AT235h tympanometer, which was possible for 399 ears. The success rate for HFT was 95.3 %. Descriptive statistics for six parameters TPP, Y 200, Y peak, Y tail, YpC-200 and Ypc-tail were analyzed and compared with previous studies. All the parameters except the Ypc-tail were in the range of previous studies.