This chapter examines the role of radiology in evaluating the abnormal auditory system, particularly in the context of implantable hearing devices such as cochlear implants and bone-anchored hearing systems. It discusses various congenital and acquired auditory anomalies, including cochlear malformations, auditory nerve abnormalities, and external ear defects. The chapter highlights how advanced imaging techniques like high-resolution CT and MRI are essential for identifying these abnormalities and guiding surgical planning. Emphasis is placed on how radiological findings impact the selection and success of implantable hearing devices, providing critical insights for optimizing outcomes in patients with complex auditory conditions. Implantable hearing devices are the devices that carry the sound energy and deliver it directly to the cochlear perilymph or stimulate the cochlear nerve and ganglion and nuclei. These devices are different from other passive devices and hearing aid devices. The indications of its usage are beyond the scope of the chapter and will be discussed elsewhere.