A guy puts a baby in a room and doesn’t talk to it to to hear the language of god..

I read this book. I was not dreaming and I cannot remember what it was called. Please help.
I was reading Paul Auster and Don DeLillo around the time.
The story is that a man wants to find the language of god so he gets a baby boy and locks him in a room and has only a mute nanny look after him and waits till he’s grown to see what language he uses to find the true language of god. The idea is an old one I think but please some tell me they read it too.