Abstract

Objectives: Bimodal fitting (BF) allows children with cochlear implant to benefit from binaural hearing advantages. Three major binaural hearing advantages, which enhance hearing function of people with normal hearing, are head shadow effect (HSE), binaural squelch effect (BSQ) and binaural summation effect (BSU). This study in pediatric patients attempting to measure the auditory benefits of bimodal stimulation in children with long-standing use of a cochlear implant (CI), and residual hearing on the contralateral side. Methods: This cross-sectional study investigated binaural advantages in 24 children of 8-12 years who had undergone cochlear implantation in a cochlear implant center in Tehran and continuously used BF. Improved score of speech perception in noise (SPIN) under BF condition, as compared to the application of cochlear implant alone, was a binaural advantage found in this study. Each binaural advantage was measured by obtaining the SPiN score under different listening and noise conditions, using relevant formulas. The measured value of each advantage reflects the improved score of SPiN, caused by that certain advantage. Results: In this study, improved mean SPiN score caused by the HSE, BSQ and BSU was, respectively, 3.13, 1.42 and 2.04 dB, indicating greater binaural advantages and hence improved SPiN, under BF condition in comparison with cochlear implant alone. Conclusion: Children with unilateral cochlear implant and measurable residual hearing in non-implanted ear can benefit from binaural advantages and better SPiN when hearing aid is used in the unaided ear.