Inner ear malformations are one of the common causes of hearing loss. Common cavity is extremely rare among the types of inner ear anomalies. In this study, 8-years development period of a boy with common cavity is presented. In case of side effect such as facial nerve stimulation or insufficient hearing and language development with cochlear implant use, auditory brainstem implant may be indicated on the contralateral side. Our case had a reimplantation due to facial nerve stimulation after cochlear implant. After the second cochlear implant activation, everything seemed fine, facial nerve stimulation was seen again in the patient and the child refused to wear cochlear implant. This suddenly stopped his auditory perception and language development. Our patient started to regress. As a team, we decided that our case needed an auditory brainstem implant. Improvements in auditory perception and language development were observed in our patient after auditory brainstem implant.