Why is this baby learning the alphabet?

He's not! However, since most of our children are highly visual learners, we can use a variety of visual cues such as signing, pictures, and written cues to increase and more importantly gain stimulus control over vocalizations.  For example, while this child was able to randomly produce a small variety of vocalizations when he began treatment, he is now able to produce many sounds with a visual cue. This will all serve to help him communicate in the future. You will see the trainer present a letter card and wait for the child to respond with the phonetic sound that the letter produces.  When he misses a response, she simply moves on to one which he can be successful at and later comes back to present the prompted trial.  This is vital for helping the child not to become prompt dependent.