Is d pronounced less forcefully in Dutch? I hear unner not onder. Though, come to think of it, I have heard some English people saying unner for under.
I guess "over het huis" could mean either "over (above) the house" or "about (concerning) the house"? Does onder have any other meanings?
"The verb hear often means we perceive or detect a sound with our ears. It is not a dynamic action but an involuntary one, hence it is classed as being a stative verb." [This means that "hearing" is not correct in those sentences"] See the explanation by Mari-Lou A here: https://english.stackexchange.com/questions/150616/is-it-really-wrong-to-say-im-hearing