4 DISCUSSION
Despite CI success in children with IEMs, the results were highly variable. In this study, we aimed to determine the success of auditory perception skills in these children over the years. The study had one of the largest series of 137 using CI children with IEMs and reported auditory perception outcomes. CT and MRI have played a critical role in the diagnosis of children with ear abnormalities; thus, surgical planning has been facilitated. However, after the surgery, it was crucial to show up the functional hearing levels of all using CI children and to know how long they have achieved their development. The auditory perception outcomes of different types of IEMs have been compared in studies.
Children with IEMs were found to develop identification and comprehension toward environmental sounds and speech sounds after an average one year. The results indicated a delay in auditory perception performance in children with inner ear anomaly; however, their performance changes with time. It is necessary to follow more closely and to study in this direction in terms of the functionality of auditory perception performances. Although the auditory performances of children with IEMs were better in the closed-set test, their vocabulary was weak, and it was observed that they had struggled in attention and memory skills during the evaluation. Open-set tests involve thinking and predicting words in sentences using clues in the context to maintain the conversation; therefore, the use of language-based visual clues would be complicated skill to develop. 10
The ten children who common cavity, incomplete partition, EVA, and membranous anomalies, in Luntz et al,12 the study demonstrated speech awareness at 25 dB HL or better. They reported that children with IEMs had more than 30 months of CI experience, and 75% of those achieved some degree of open-set sentence recognition. Dowell et al,13 showed that children implanted before the age of four years had mean scores of 68% for open-set phonemes after three to five years of experience with the cochlear implant. The present study results showed that after one-three years of CI experience, children with IEMs have succeeded in the closed-set test, but not in the open-set SRT test.
Overall IEMs, the EVA group had a higher score than normal cochlea in the closed-set test. The EVA was a congenital anomaly with progressive sensorineural hearing loss. In the beginning, their hearing may be normal, but the process is progressive. It was thought children with EVA might have been suffering from HL in the peri- or post-lingual period rather than the prelingual period. EVA was better than IP-II because of the better than the modiolar defect, which is the reason to make the outcome slightly worse. EVA, IP-II, IP-III had comparable results with normal cochlea; this is because a good-sized cochlear nerve always accompanies them. ABI surgery is never indicated in EVA, IP-II, and IP-III. Some studies in the literature have shown that children with EVA exhibited high performance in auditory perception testing.14-16
As higher-level language skills had increased, it had been determined that children with IEMs (especially common cavity and cochlear hypoplasia) have difficulty with comprehension skills. Results indicate that the duration of CI use is significant than the chronological age for both receptive and expressive language development. As the child’s chronological age increases, the gap between language skills scores wider. In later years, it will be challenging to learn comprehensive language skills and catch these tasks.17Tucci et al,18 reported the same finding in their study with five children and one adult. All patients except one demonstrated limited language skills.In another study, researchers presented speech perception and production after follow-up for 36 months in children with common cavity scores for the CAP, SIR, MAIS, and closed-set/open-set auditory speech perception tests were lower than in the control group. Both of these studies reported lower results than the present study.19
Parents should be informed before surgery about the possible effects of ear anomalies on auditory performance and language skills. However, a comprehensive preoperative radiological examination, successful surgery, and an individually tailored postoperative rehabilitation program should be included.