I've heard phrases similar to
It was if they wear hearing me but they weren't listening
My first request is what are the common forms of this statement as I've heard some that seem more logical than others.
What precisely does the phrase mean? I believe taken literally it's an oxymoron as most dictionaries define hearing and listening very similarly. From the definitions I've red, listening tends to imply that the sound being heard carries meaning (but don't all sounds?). For example you could say "listen to his instructions to know what to do" but you could also listen to something non-verbal to gain information, for example if you heard a tree come falling down, you know that a tree fell down.
For the over all meaning of the phrase, I can think of a few different meanings and was wondering if any are right or wrong:
The person was perceiving the message but knowingly chose not to comply. e.g. Joe heard Bob tell him to come early but he chose to disregard the request.
The person's capacity to hear is working well but cognitively he is disengaged. e.g. Joe stood in front of Bob while Bob was talking, but Joe's mind was elsewhere.
The person is incapable of interpreting the message. e.g. Joe doesn't speak the language Bob was speaking to him in.
This is what I don't get, in example 3. most people would say Joe was listening to Bob but couldn't understand him. So this seems to show that the phrase in question missuses the word "listen".
TL;DR In a sense I'm asking what the difference is between "hearing" and "listening" and if the quoted phrase is an idiom in the sense it does not logically apply the rule.