I think JAK has hit exactly what I was trying to say. "Listening" is an active verb. It means you're trying to do something. No, we don't need to listen to nature. But it is good to hear nature. Sometimes listening serves as a filter - as in when one is at a party, listening to just one person while to the exclusion of the crowd.
"Hearing" simply means that the sounds hit your eardrum; you're not filtering them, much as "splatter vision" works (q.v.). It's sort of the distinction between "doing" and "being". It's a good thing, and hiking is ideal for it: While you are, in fact, "doing," you can let all your senses and consciousness allow the world to touch them without actively needing to focus. Not always, of course: When you ford a stream, it helps to focus on where you step. But much of the rest of the time, the Buddha in your backpack will let you exist in the world just fine.
Or not. Doesn't really matter.
TW