For him, and for the time being, it is normal. The negative effects will be seen later. Try to drag him out of his room and introduce him to real people, because all he knows now are messenger id's. Take him to clubs, to the gym, to a tennis court, to the swimming pool... Not matter where, just take him out of his room. He'll thank you later.
On the other hand, diversity is vast among human beings, he could fit perfect into a human category and live happily until his last day. You never now. Anyway, listening to music for hours is not as bad as it seems.