Multiple-frequency Tympanometry In Adults With Otitis Media With Effusion

Objective To investigate the diagnostic value of multiple-frequency tympanometry (MFT) and conventional 226Hz tympanometry in adults with otitis media with effusion(OME).Discuss whether the resonant frequency(RF) can be used to be one of the reliable methods in adults with otitis media with effusion. In a 3-moth follow-up period, the changes of MFT and conventional 226Hz tympanometry were recorded to investigate whether the resonant frequency may be more sensitive and objective in OME sequelae than single-component tympanometry.Method Prospective study was applied to compare the normal hearing group and the group with OME. One hundred and twenty one ears were included. The outcome of otoscopy, pure tone audiometry and GSI-33 middle ear analyzer was considered standard. Eighty-five ears were divided into OME group which were diagnosed with OME by ENT doctors, had conductive or mixed hearing loss, air-bone gap was more than 10dBHL and acoustic reflex was not elicited. Thirty-six ears were divided into normal hearing group(pure tone threshold≤15dBHL, air-bone gap≤10dBHL). The mean of RF value was recorded. Levene's test was used to test the difference between the OME group which in dayl,day15, day30,day90 and the normal hearing group. P＜0.05 is considered statistic difference. A 95% range of RF values from normal hearing group was considered standard to distinguish normal from abnormal RF values. Compare the relationship among multifrequency tympanometry, 226Hz tympanometry and acoustic reflex test in ears recovering from OME. Use Spss 12.0 to do statistic analyze.Results There was found to be a statistically significant decrease in RF values in ears with OME compared to normative data. In consecutive visits,the RF values increased and the percentage of type A tympanograms increased whereas the percentage of type B and C tympanograms decreased. The mean RF valve for day90 was still a little difference with that in normal hearing group though it was near to the normal range. The resonant frequency range from 900Hz to 1100Hz was considered normal from our findings. There was found high agreement between middle ear resonant frequency test and acoustic reflex test in ears recovering from OME.Conclusion The middle ear resonant frequency in adults range from 900Hz to 1100Hz was considered normal. There was a significant decrease in RF values in adults with OME. With the recovering from OME it can increase to normal range. Because of the high agreement between resonant frequency and acoustic reflex, the recovering of RF can be used to indicate the completely recovering of the middle ear function. According to our findings, the abnormal RF values persist longer than conventional tympanometry indicate. The resonant frequency can provides more detailed information that 226Hz tympanometry is unable to detect. So multiple-frequency tympanometry may be more sensitive and objective in adults with OME and very useful for ENT doctor.