1 INTRODUCTION
Cochlear implantation (CI) has become a life-transforming device for children with severe and profound hearing loss (HL). However, in the beginning, CI was a contraindication for inner ear malformations (IEMs), which are, constitute approximately 20%–35% congenital sensorineural hearing loss cases.1-4 Preoperative audiologic and radiologic evaluations are very important for cochlear implant candidates. With advanced imaging techniques such as CT and MRI, cochlear structures could be appropriately evaluated. With these advanced techniques, cochleovestibular malformations were classified, and it was reported that the majority of children with IEMs anomalies have bilateral severe to profound HL and are candidates for either CI or Auditory Brainstem Implant (ABI).5-7 It was known that CI is an effective treatment modality for individuals with IEMs. Sennaroglu and Bajin5 were classified IEMs eight groups: Complete Labyrinthine Aplasia (Michel Deformity), Rudimentary Otocyst, Cochlear Aplasia, Common Cavity, Cochlear Hypoplasia, Incomplete Partition of the Cochlea I-II-III, Enlarged Vestibular Aqueduct, Cochlear Aperture Abnormalities. The incidence of IEMs was reported at 11.5% in our clinic.3
Cochlear implant outcomes depend on different parameters such as onset and duration of HL, the age at implantation, presence of neurodevelopmental disorders, the anatomy of the inner ear and physiology of the auditory nerve, family support, socioeconomic level, access to rehabilitation services, and regular CI programming. Important information about cochleovestibular anomalies has allowed in the preoperative period with advanced technology in imaging methods.6,7 Because of comorbidity of IEMs with different types, especially children, could be suffering from auditory perception. Many studies have compared the speech perception and language skills of children with and without IEMs. A study by Farhood et al,8 showed the benefits of CI in the speech perception of patients with IEMs. Eisenman et al,9reported that the progression was slower in children with IEMs for auditory perception.
In the current study, the principal objective was to compare the preoperative and postoperative auditory performance of children with and without IEMs. The specific objective of this study was to elaborate auditory perception outcomes of IEMs types.