The Use of COSI Questionnaire to Evaluate the Effect of Input Dynamic Range Variables on Cochlear Implant Performance in Postlingual CI Adults
Tarek Abd El-Aziz Ghannoum, Mona Hassan Selim, Amira Maged El-Shennawy and Zahraa Mohamed Yousry Elbohy
Journal Title:Acta Scientific Otolaryngology
Background: If our goal is to obtain optimal patient performance in everyday life; clinical fitting should improve the cochlear implant (CI) users’ ability to understand soft speech as well as speech in noise. It is of great value to change the input dynamic range (IDR) characteristics for CI performance optimization in daily life. Aim of work is to use the Client Oriented Scale Improvement (COSI) qu-estionnaire for evaluation of the effect of different IDR characteristics on CI performance.Methods: The study group is comprised of fourteen postlingual CI adults who were implanted and used their devices for at least 6 months. Programs were adjusted for four input sensitivity settings differing in threshold (T) and comfortable (C) levels, microphone sensitivity (MS) and volume sensitivity. Subjects were assessed subjectively by using COSI questionnaire 2 weeks after each program setting.Results: The commonest specific needs in the patient population were firstly to hear conversation with group in noise. Both 3rd and 4th programs revealed the highest percentage of hearing final ability at both 2nd and 3rd important listening situations. This means that patients preferred the programs with the maximum microphone sensitivity, and C level set below MCL.Conclusion: COSI questionnaire highlights the specific needs of the CI user referring to the advantages of the CI in those situations. High microphone sensitivity settings might make low-level sounds more audible. C level might need to be reduced to an acceptable level. Based on our results, high microphone sensitivity and setting of C level below MCL should be taken into consideration.