Wideband Absorbance Outcomes of Cochlear Implantation: A Comparative Clinical Study

Abstract

Wideband tympanometry (WBT) measurements show sensitivity to trends in external ear canal/middle ear maturation and changes in middle ear status as a result of different types of dysfunction. This study aims to determine the effects of cochlear implantation (CI) on middle ear status. This is a prospective comparative clinical study that has been done in a tertiary referral center. The patients who underwent unilateral cochlear implantation were included in the study. All the participants were under 18 years of age and had congenital bilateral profound sensorineural hearing loss (SNHL). WBT measurements of implanted ears were calculated and compared to those of non-implanted ears (control group) in the same patient group. The differences in these measurements were subjected to statistical analyses. A total of 48 patients (96 ears) who underwent unilateral CI were included in the study. Our study revealed that significant reductions in the average absorbance ratios occurred at all measured frequencies and that the average resonance frequency increased more significantly in the implanted ears compared with those of control group (p<0.001). The difference in the average peak pressure was not significant among two groups. (p=0.211) CONCLUSION: This study shows that the average absorbance ratio decreases and average resonance frequency increases after cochlear implantation. These findings may be related to increased stiffness in middle and inner ear system. Future studies are needed for more detailed information and recommendations on this topic.