Communication

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Communication is our expressive language, however we may do it and requires motor planning, sequencing and co-ordination. As infants our primary source of communication is crying or facial expressions, how ever language rapidly develops and it is said that by the age of 3-4 we use on average 2000-3000 words. As we mature being able to communicate effectively with others is essential to our independence and peer acceptance which become of increasing importance going in to our teenage years.
As a result of the inability to communicate effectively, problem areas may include coping skills, self regulatory behaviour, engagement in social interaction, development of healthy attachment with parents/caregiver/peers, self expression and development of self concept. these can influence a child's ability to play, establish routines, learn new skills and establish relationships. (Merrill, S.C., Mulligan, S.E. 2003) 
So you see why it is so important that a child is enabled with an ability to communicate and is an important focus for treatment. 

Here a clip that gives the run down on AAC, this seems to be a common tool used for communication so have a look. 

Perhaps a bit more appropriate in today's day and age however is the numerous iPod, iPad and iPhone apps, this clips gives a bit of a run down on a range that are around. 


References
         Merrill, S.C., Mulligan, S.E., (2003). Neurological dysfunction in children. In E.B. Crepeau, E.S. Cohn, & B.A. Boyt-Schell (Eds.), Willard and Spackman's occupational therapy (3rd ed., pp. 699-716). Philadelphia: Lippencott, Williams & Wilkins