Myth 1: AAC is a "last resort" in speech-language intervention.
The use of AAC interventions should not be contingent on failure to develop speech skills or considered a last resort because AAC can
play many roles in early communication development. In fact, it is critical that AAC be introduced before communication failure occurs. This change means that AAC is not only for the older child who has failed at speech development but also for a young child during the period when he or she is just developing communication and language skills, to prevent failure in communication and language development.

Myth 2: AAC hinders or stops further speech development.
This fear that many parents, and some practitioners, have is simply not supported by the available empirical data. The literature actually suggests just the opposite outcome. There are a modest number of empirical studies that report improvement in speech skills after AAC intervention experience. For very young children, the use of AAC does not appear to hinder speech development (Cress, 2003). In fact, it may enhance the development of spoken communication, which should be a simultaneous goal for intervention.

Myth 3: Children must have a certain set of skills to be able to benefit from AAC.
In the past, young children with some degree of cognitive disability were frequently excluded from AAC intervention because their assessed levels of intelligence and their sensorimotor development were not commensurate with cognitive/sensorimotor skills that had been linked to early language development. While one may argue that some basic cognitive skills are essential for language to develop, the exact relationship between language and cognition have not been specified clearly. Investigators have argued against excluding children from AAC interventions based upon intellectual performance and/or prerequisite sensorimotor skills. Given the overall impact language exerts on cognitive development, a lack of expressive language skills may put an individual at a distinct developmental disadvantage. Developing language skills through AAC may be of critical importance if the individual is to make functional cognitive gains as well.

Myth 4: Speech-generating AAC devices are only for children with intact cognition.
Newer devices sometimes require little skill and can provide a place of introduction to AAC for the young child. The AAC device is simply a tool, a means to an end—language and communication skills—not the end in itself. Having a voice at a young age can facilitate self-identity as well as communication.

Myth 5: Children have to be a certain age to be able to benefit from AAC.
Current research clearly documents the efficacy of communication services and supports provided to infants, toddlers, and preschoolers with a variety of severe disabilities.

Myth 6: There is a representational hierarchy of symbols from objects to written words (traditional orthography).
This myth suggests that a child can only learn symbols in a representational hierarchy. The hierarchy begins with real objects to photographs, to line drawings, to more abstract representations, and then to written English words (traditional orthorgraphy). evidence from the literature on typical language development suggests that this myth is not based on evidence about how young children learn. In fact, during early phases of development, it may not matter if the child uses abstract or iconic symbols because to the child they all function the same.

Link to article

Romski, M., & Sevcik, R. (2005). Augmentative communication and early intervention: myths and realities. Infants & Young Children: An Interdisciplinary Journal of Special Care Practices, 18(3), 174-185.