Augmentative and alternative communication (AAC) includes a range of approaches aimed at supporting or replacing speech for children and others for whom natural speech is not sufficient to meet their needs. For some children it also offers a support to the process of language learning. A wide range of medical conditions may lead to a child requiring AAC, either temporarily or on a more permanent basis. AAC systems may be unaided or aided, in the sense of requiring some form of equipment. They vary on the level of technology required from none to specialized computer-based devices offering synthesized speech output. Management of children requiring AAC must involve parents and a multidisciplinary team of health and education professionals, in addition to active involvement on the part of the child.