Post-surgical changes in wideband absorbance in paediatric cochlear implant users after mastoidectomy and posterior tympanotomy.

Abstract

Background: Although Cochlear implantation (CI) is effective in restoring hearing for children with severe-to-profound sensorineural hearing loss, it may influence the middle ear mechanics, potentially causing an air-bone gap and altering middle ear stiffness, which is not detected by traditional 226 Hz tympanometry.

Aims/objectives: To investigate the effect of mastoidectomy posterior tympanotomy (MPTA) on wideband absorbance (WBA) in children with CI.

Materials and methods: The study included 20 normal-hearing children (normal group) and 10 children with CIs who underwent MPTA (CI-MPTA group), aged 3-10 years. WBA at peak and ambient pressure, resonance frequency, and 226 Hz tympanometry were measured.

Results: The normal group showed maximum absorbance at 1250 and 3000 Hz, whereas the CI-MPTA group had a single peak at 3000 Hz. The CI-MPTA group exhibited reduced absorbance at low and mid-frequencies (250-1500 Hz), with significant differences (p < 0.05) observed at 800-1250 Hz for peak pressure and 1000-1250 Hz for ambient pressure. No significant differences were found in resonance frequency or 226 Hz tympanometry.

Conclusions and significance: CI with MPTA changes middle ear absorbance patterns, affecting the low- and mid-frequency regions. These findings indicate the importance of using WBA tympanometry to monitor middle and inner ear mechanics post-CI.