Cochlear implants have raised questions about how children with profoundly impaired hearing can learn spoken language. This study addresses the question of whether there is a critical level of hearing for the development of adequate speech perception abilities. A comparison of the relationships between speech perception scores and spoken language scores shows that a group of profoundly deaf children using hearing aids process spoken language in a way that is fundamentally different from two groups of children with severe and moderate hearing losses. We infer that there is a critical level of hearing below which speech perception relies very heavily on linguistic processing to compensate for limited auditory, information. We also show that a cochlear implant can promote profoundly deaf children from below to above the critical level of hearing.