In/within earshot (of somebody/something) phrase
Opposite phrase: out of earshot
Near enough to someone/ something to easily hear what they speaks or does.
As I came within earshot of the basement, I heard a spooky sound coming out of it.
Mary didn't notice that I had been in earshot of her the whole time she gossiped about me.
John told Mary to go outside because he didn't want to talk when everyone in there was in earshot.
The phrase is American in origin though the literary origin could not be traced accurately. It is one of the phrases which comes from the real life conversion of an event into an idiom.