Not only it doesn't require "możesz", it would make the sentence quite odd.
Basically, when in English you use "can you hear"... do you really mean "are you able to hear it or is it too quiet"? I don't think so. The meaning is rather the same as "do you hear". The same happens with "do you see/can you see".
So if you use "możesz" in Polish in this sentence, you effectively try to create a sentence equivalent to "Are you able to hear it?". And yes, it would take infinitive, but actually not infintive of "słyszysz" (that would be "słyszeć"), you'd need a perfective verb (perfective verbs focus on the moment something 'succesfully' happens, not on the process, like imperfective ones). So that would be "Czy możesz to usłyszeć?". This one would be correct, but still pretty odd and rather unlikely.
Ok thanks. I guess that this whole perfective verb vs imperfective verb is a bit too soon for my level.
But I'm glad I was correct that możesz would be followed by infinitive.
And yes, you are right that, when we say "can you hear that" we usually don't mean "are you able to". We mean "do you?"
Although, strangely, when we say "can you pass me the salt", we don't mean "are you able to", - in that setting "can" means it is a request.
In contrast, at school, if we ever asked our teacher "Sir, can I use the toilet?" we used to get a sarcastic reply like "I don't know, you tell me... Can you?"
The joke being that "can I" means "am I able to" and we were supposed to ask "Sir, may I use the toilet...?"
So 'Can' can mean a request, or the ability, or do you, etc etc
Perhaps możesz has some of these variations too though so far I have only ever used mogę to make an offer. Eg.. I can help you