So does hört mean both hear and listen? Because in english if you say "he does/will not listen" it means he is stubborn and will do what he wants regardless of what anyone says; whereas if you say "he does not hear" it means he's deaf.
I disagree that "hören" can mean "hear" and "listen." I think German does make the distinction that LB_StorM draws attention to in English. I think that this sentence would definitely imply that he is deaf, or at least that the sound waves are not reaching him, for whatever reason. If you wanted to say "He does not listen", "Er hört nicht" would sound incomplete to a native speaker. "Er hört nicht zu" would make it clear that he is acoustically hearing but not listening (in the sense of obeying). You could also use the preposition "auf" if there is something specific he is not listening to: "Er hört nicht auf mich" -- "He doesn't listen to me."
"Er hört nicht" means "He doesn't listen" in the sense of "He doesn't obey".
So it depends on context and intonation? Because hearing and listening are very different...
Why isn't this "he does not hear" as opposed to "he does not listen"? It seems like both are reasonable interpretations of the sentence.
"He does not hear" wouldn't be a proper sentence because it is missing the subject; what doesn't he hear? So technically shouldn't you only accept "He does not listen," since "He does not hear" would be "too awkward?" (according to Christian the moderator)