The effect of frequency modulation system on learning in first grade students with cochlear implantation

Objective: Children with cochlear implant (CI) often experience difficulty in listening and speech-perception in classroom settings due to significant detrimential effects of increased background noise, reverberation time and speaker-listener distance. Frequency modulation (FM) systems are offered as a possible solution to these problems. FM systems are listening assistive devices which transmit the signal to the listener directly from signal source to decrease acoustical problems by increasing signal to noise (S/N) ratio of CIs. The purpose of this study is to determine whether FM system has an effect on learning level of children with CI who are fitted with FM. Material and Method: The children with unilateral implant for at least three years and who started the primary school were included in this study if they inhabited in İzmir and around. Twenty children were defined as appropriate according to the inclusion criteria. Denver II Developmental Screening Test was performed for assessing the general development of children; resessive and expressive language development level with TIFALDI test and primary school readiness level with Metropolitan Readiness Test. Statistical z- scores of every children were calculated according to the distribution of the tests. After pair-matching, 10 children were included into the CI group, and 10 into the CI+ FM system group. CI group did not use any hearing assistive device while the CI+ FM system group used FM system regularly. One subject from the CI group and two from the CI+FM group did not attend evaluation tests at Month 3 and were excluded from the study. Therefore, 17 subjects completed the study. Achievement tests that are appropriate for fundamental acquisitions in Turkish, Mathematics and Social Science lessons were developed to assess the learning level, validity and reliability. The same tests were applied to the 67 normal hearing children who were attending the same class of study subjects in both groups to exclude the individual factor related to the teacher. The tests were applied to the study subjects of both groups at baseline and at intervals of three months, four times as a total while the healthy children were evaluated only twice, at baseline ant at the end of the study period. Results: According to the results of the analysis, a significant increase in success is noticed (p<0.05) over the period of the survey for the students in every area of the two groups. Over time, the CI+FM system group demonstrated more development in Mathematics, and the areas of listening and reading comprehension of Turkish lesson and Turkish lesson in general compared to CI group. It is therefore concluded that the use of FM system increased the success rate noticeably in those areas statistically compared to the use of CI alone (p<0.05). No significant statistical difference can be observed between the learning level of the two groups in social science lessons and the dictation and reading-aloud components of Turkish lesson (p>0.05). However, it is apparent that the overall success of the CI+FM system group in every lesson increased over time compared to the CI group alone. Conclusion: According to these findings, it can be assumed that use of FM system contributes to the learning in children with CI significantly. However, it requires more studies to be performed to show the benefits of FM system in educational settings. Key Words: Cochlear Implant, Assistive Technologies, Achievement Test, Learning