Background and Aim: Theory of Mind (TOM) refers to the ability for attributing mental states and beliefs to ourselves and others, and understanding that the others’ mental states can be different from ours. However, this ability seems to be delayed in children with the history of hearing impairment. Based on the evidence, there is a mutual association between language development and social experiences. The present study aimed to assess TOM and the effect of speech therapy in 8- to 9-year-old children with cochlear implants (CIs).Methods: The present study was descriptive and cross-sectional in design. A total of 18 Persian-speaking children with CIs and 18 normal children aged 8-9 years participated in the current study. Children with CIs were selected through convenience method from Amir Alam Hospital and normal peers from their play-ground. The participants had no history of sensory, anatomical, neuronal, and speech disorders. The basic and advanced TOM was assessed with Ghamarani TOM test and a comparison was done between normal children and children with CIs. The obtained data were analyzed by SPSS 21.Results: The performance of the two groups with regard to the basic and advanced TOM was significantly different (p<0.001). Moreover, there was a significant positive correlation between the duration of speech therapy and TOM abilities (r=0.46, p=0.041).Conclusion: Hearing impairment affects the ability of TOM in children with CIs. The duration of speech therapy has a positive effect on the development of TOM.

Background and Aim: Theory of mind (ToM) is very necessary to have successful social interaction. Hearing impairment disrupts the ToM development and language acquisition. This study aimed to compare ToM abilities of children with cochlear implant (CI) and normal hearing (NH) to clarify the role of language skills in ToM development. Methods: Participants were CI and NH children in two age ranges of 5−6 and 8−9 years. Main measures were basic and advanced tasks of ToM test (Abbreviated as B. ToM and A. ToM), and comprehension of mental–state verbs and relative clauses. Regression analysis was used to assess how language skills predict ToM. Results: CI children obtained significantly lower scores in all subscales of ToM test (p ≤ 0.001). Regression models for CI group aged 5−6-year showed that their comprehension of mental-state verbs predicted 53% of B. ToM. In CI children aged 8−9 years, comprehension of relative clauses and mental-state verbs together predicted 61% of B. ToM and 73% of A. ToM variances. Furthermore, comprehension of rela­tive clauses predicted 43% of B. ToM and 31% of A. ToM in younger NH children. Conclusion: Comprehension of mental-state verbs can predict only B. ToM in CI children aged 5−6 years and both B. ToM and A. ToM in CI children aged 8−9 years. Therefore, it is the main factor to predict ToM ability of preschool and school-age children with CI. The role of language should be considered by people who are helping these children for their cognitive problems. Keywords: Theory of mind; mental verb; relative clause; cochlear implant