Comparison of Electroaudiometry with cochlear implant in children with inner ear anomaly

The promontory stimulation test (PST) using a needle electrode has been used to evaluate the sense of the auditory nerve as a preoperative examination for cochlear implant in adults. Because this is a painful test, it is not suitable for children. It has been reported that children with inner ear anomaly showed poorer outcomes of hearing after cochlear implant. Electroaudiometry developed by Med-El Corporation, which is noninvasive, is a more suitable procedure for young children. Patients were three children less than five years old with inner ear anomaly. Two patients showed common cavity, and one showed narrow IAC with hypoplastic cochlear anomaly. By using Electroaudiometry, we analyzed electro-neural hearing of these children before cochlear implant, and compared their hearing after cochlear implant. Three children seemed to have residural electro-neural hearing because the dynamic range between stimulus level (SL) and uncomfortable level (UCL) was detected by using Electroaudiometry. After cochlear implant, their pure-tone audiograms showed moderate hearing thresholds, and their hearing detection and speech perception improved. These results suggest that Electroaudiometry is available for evaluating electro-neural hearing in young children with inner ear anomaly. It can provide useful information for a successful cochlear implant and evaluation of postoperative performances.