Ear infections are the most common reason for Canadian children to visit a doctor. Chronic ear infections can have persistent effects on all aspects of language development, especially if they begin during the first year of life. The purpose of this project is to investigate the impact of early-onset otitis media (Otitis Media with effusion refers to the condition involving the presence of fluid in the middle ear, with or without an accompanying infection) on speech perception and speech production development in infancy, with a view to developing tools for early identification and intervention for OM-related speech and language delay. The specific objectives are to assess middle ear function, hearing acuity, speech discrimination, selective attending, speech production (babbling), and early vocabulary and word learning skills on a longitudinal basis from 2 through 18 months of age. The measure of selective attending will be developed specifically for this project. Data analysis will be directed at testing the hypothesis that auditory attention to speech is an intervening variable that may explain some of the between-subjects variability that is observed in the outcomes associated with early onset otitis media.