Multicomponent tympanometry in ears with cochlear implant

Abstract

Abstract Introduction: Multifrequency and multicomponent tympanometry procedures enable the evaluation of minute changes in the middle ear system and the estimation of resonant frequency. Changes in the resonant frequency beyond normative values indicate the presence of pathology or change in the natural characteristics of the middle ear. The present study aimed to investigate if there is a difference in the admittance of the middle ear on the side of cochlear implantation and the contralateral ear for different probe tones. The study also investigated if there was a difference in the type of multicomponent tympanogram obtained in ears that have undergone cochlear implantation when compared to the contralateral ear. Methods: Twenty children in the age range of 4–14 years with bilateral severe to profound sensorineural hearing loss, having undergone unilateral cochlear implantation, were included in the study. Tympanometry using four probe-tone frequencies (226 Hz, 678 Hz, 800 Hz, and 1000 Hz) was carried out in each ear. Total compliance (Y) and type of tympanogram were compared across the ear with cochlear implantation and the contralateral ear. Results: It was found that the implanted ears had lower mean admittance values as compared to the contralateral side at all four probe-tone frequencies. Wilcoxon signed-rank test indicated that the difference was statistically significant for 226 Hz, 678 Hz, and 800 Hz probe tones, suggesting increased stiffness in the ear with cochlear implantation. There was a significant difference in the type of tympanograms obtained in the two ears for 800 Hz and 1000 Hz probe-tone frequencies. Conclusions: These results warrant the testing of the contralateral ear for obtaining electrically evoked stapedial reflex thresholds (eSRT).