i am partial deaf so i could hear with help of hearing aids. i only wear one hearing aid but i was told to wear two hearing aids as it could improve my hearin but i find it difficult to hear right if i wear 2 so i only wear one, without hearing aid, i could hear sound but it's not great, i would hear like vibrate from mobile on wood table, it made awful noise and i respone to it without hearing aids. or people talking in quiet time especially in morning cos it's quiet in morning right? so i could hear people talking but i wouldn't understand what they are saying. just hear sound of talkin, hard to explain though. i dunno if your son could hear or not, in ireland where i am living present, i only know one deaf girl who has cf, she is 19, she is partial deaf but her voice is low, hard to hear her talking. so that all!!! if i was suppose to answer your question, pls feel free to ask! i may take time to reply as i am not on for 24/7 lol so god bless