..wel you get the picture.
He literally never shuts up. If we are having stories he talks or sings all the way through- not neccesarily about the story either. He ttalks through tv programmes or dvds, he talks when there are other grown ups around - getting louder and louder even is asked to be quiet.
He talks whilst eating, drawing playing etc.
Today a lady came to the door to check up on some work that had been done and I still don't know what she wanted as I couldn't hear a word she was saying as he was talking louder and louder over her and me.
I have tried
"when grown ups are talking you need to be qiet"
I have tried answering him straight away, even when i am talking to another adult - doens't work
I have tried asking him to shush and put a finger over his mouth, he does that but still talks with the finger over his mouth.
He goes to pre school and they say he never stops talking there either in fact the teacher there asked me what he was like at mine as she said he interupts story time or quiet time or "round in a circle time" because he talks and talks and they say that even their techniques for managing chatterboxes aren't working. Repetition is a big thing with him too. it is wearing me down, it's affecting how i mind the other children, as when we try to have group stories he is talking all the way through them, he is talking while I am talking to other mindees their parents etc.
he doesn't seem to get " shush" "or " quiet" and even asking politely to shush when i am trying to tell a parents what her child has done that day is impossible. One parent refuses to come in the house now 
I have a headache every singel day by 3pm and am sometimes nearly in tears (and I have been a CM for nearly 10 years) and it's relentless, anyone have any coping or managing techniques?