Can I say "those listening" in place of those who listen, and "those who listen" instead of those listening?
It would be grammatically correct to do so. However, by reducing the clause to a phrase, "listen" becomes "listening", which seems to convey the idea that the people you refer to in this sentence are listening now or at this moment. This is interesting because I don't think it often works out this way when it comes to reducing clauses to phrases. This is a good example of how mechanical grammar can be. I think a native speaker would avoid reducing this particular clause to a phrase quite naturally, and, of course, without even thinking about it. Most native speakers don't know what "reducing a clause to a phrase" means, anyway. So it's possible, but it seems to make the intended meaning somewhat unclear.