Abstract
BACKGROUND: The technical inspection of internal and external components is an integral part of cochlear implant (CI) aftercare. The speech processor (SP) is routinely checked to ensure that the microphones are fully functional. Depending on the SP, these can be listened to by specialist personnel or checked in the CI fitting software. Microphone defects can also be revealed by poor hearing performance. Modern CI systems also record the duration of use of the SP and exposure to certain listening environments via data logging. In a bilateral CI fitting, large deviations in the detected hearing environment between both processors could indicate faulty microphones. The aim of this study is to compare the data logging entries of bilateral CI users in order to identify potential microphone failures. METHODOLOGY: The retrospective data analysis includes 359 bilateral CI users who received a Cochlear Nucleus 6 system or higher. The individual data logging entries were analyzed with respect to the duration of CI use and duration of the listening scenarios quiet, speech in quiet, speech in noise, noise and music and both sides were compared. With a comparable duration of CI use, deviations of more than 15% between the listening scenarios of the left and right SP were considered conspicuous. RESULTS: Of the 718 SPs examined 9 were rated as conspicuous. With a comparable CI use of the left and right SP, significant differences of up to 54% were detected between the two devices in the quiet listening environment. One of the SPs recognized only the quiet scene to 100%. Based on two case examples the period of the patient's wearing behavior, the listening environments and the detectable differences between the two individual SPs during CI aftercare are presented in detail. CONCLUSION: The information from the data logging enables the detection of possible microphone defects. The data are automatically read out and displayed anyway during the CI fitting. It is recommended to integrate the data logging information into the clinical routine as part of the technical check.