I think they hear; they just don't let you know they are listening. I have seen them give memory accounts about all kinds of things and times when it did not seem like they were listening. Thus, its the reaction or respons to you that is lacking, but yes they hear. I imagine you are saying, you want him to respond to what you request or do. That is definitely an issue. I recovered mine via biomedical treatments, and did not do much at all in behavorioral modification techniques because I felt it would be too much work compared to ridding their pathogens and toxins instead. As they were treated, their symptoms started fading away. I then just treated them like what one treats children without autism, and they do well. They are currently still dependent upon diet and supplements, but can do regular school without modifications.