system
A chat on subreddit /r/NoStupidQuestions
human
You’ve hit the crux of it:  Is “sound” the existence of pressure waves, or is it the act of observing these waves through your ears?  It’s purely philosophical with no correct answer.  Does sound require an observer to change from “waves” to “sound?”
gpt
I disagree, this is not the crux of the question. The question you describe here is simply a semantic one: how do we define sound? We may define it as pressure waves or as the observing of pressure waves.

However, this is not really interesting in my opinion and does not describe the point of the question. Rather, the question asks whether or not these sound waves, which we call sound, exist at all when they are not observed.
Or more generally, does a world exist at all outside of our perception? 

Think of a single player video game. The world around the character is continuously rendered directly around that character, but is not continuously rendered outside of the characters perception. Hence, there are no trees falling and no soundwaves created outside the room a character is sitting in.