Hear

Hear
 

If John wants to say he does not have the experience of hearing people use a certain phrase, could he use of in the blank?


-John's never heard __ it.

My friend says with or without of, they are the same; but using of sounds wrong to me.(Since it is talking about actually hearing things, then of should be wrong; if you use of, it means you know about the existence of it; but I'm not so sure)