Abstract
This study used the largest and youngest cohort of hearing impaired (HI) children to investigate the effect age at implantation had on the trajectories of expressive and receptive language, and externalizing behavior problems. In addition, the temporal relationship between language and externalizing behavior problems was examined in children implanted before and after the age of 2. Univariate latent difference score analyses were conducted to test the effect of age at implantation on each trajectory and bivariate difference score analyses were conducted to test the temporal effect between language and externalizing behavior problems. Results showed that age at implantation had an effect on the initial level and growth of expressive and receptive language trajectory and an effect on the initial level of externalizing behavior problems. Expressive language was found to have an influence on the changes in externalizing behavior problems for both groups, children implanted before and after the age of 2. However, the relationship between receptive language and externalizing behavior problems differed between the two age groups. The effect was bidirectional for the younger group but unidirectional for the older group, with externalizing behavior problems influenced the change in receptive language. Future research and potential interventions to improve behavior difficulties in deaf children are discussed.