Research shows that children with communication challenges do best when introduced to augmentative and alternative communication earlier
"For young children with complex communication needs, augmentative and alternative communication (AAC) devices and strategies can be key to their development of language, literacy, and communication and cognitive skills. The earlier AAC is incorporated into their lives, the greater the potential for improving their outcomes."
This article notes stages of language development, issues encountered by children with communication needs and provides detail on interventions and their benefits, including manual sign and a total communication approach. While the legislation mentioned pertains to the US, the rest of the article is relevant and of interest to those supporting AAC users including those using Lámh signs.