[Analysis of the 1000 Hz tympanometry in normal hearing neonates].

OBJECTIVE: To analysis the clinical characteristics of 1000 Hz probe tone tympanometry obtained from normal neonates who passed the OAE screening. To calculate the normal range of the variances of the tympanometry, which may serve as the guide for newborn hearing screening and detect middle ear function in neonates. METHODS: OAE screening were performed to screen the hearing with GSI-70 Automated OAE. The 1000 Hz probe tone tympanograms were obtained from 650 neonates who passed the TEOAE screening in both ears and were on the normal physiological conditions after birth with GSI Tympstar Version II Middle Ear Analyzer. The means, the standard deviation, the 95% confidence interval were analyzed. RESULTS: The 1000 Hz tympanometric data showed the 1Y1B1G tympanogram in 732 ears (56.3%), the 1Y3B1G tympanogram in 145 ears (11.2%), the 0Y0B0G tympanogram in 269 ears (20.7%), other shapes in 154 ears (11.8%) according to the Vanhuyse model. The 1000 Hz tympanometric datas showed the single-peaked tympanogram in 967 ears, the 95% confidence interval of the tympanometric data were as follows: tympanometric peak pressure (Tpp) was from -55.0 to 180.0 daPa, peak compensated static acoustic admittance (Peak Ytm) was 0.03-1.18 mmHo, tympanometric width (TW) was 70.0-230.0 daPa. CONCLUSIONS: The majority of 1000 Hz tympanograms from this study show the single-peaked in normal neonates. The 95% confidence interval of the tympanometric data may serve as a guide for hearing screening and detecting middle ear function in neonates.