Yes, sounds are waves that go thru a medium, usually air.

Think of it like one person speaking in a gym compared to 1,000

The different sounds add up, that’s easy everyone just has to talk. But you don’t get silence, you get a cacophony.

To produce opposite sounds to cancel each other out though, that would be impossible, and becomes even more impossible as you scale up.

It helps if you can see it to visualize what I mean by alternating waves:

askamathematician.com/…/Noise-Cancellation.gif

I didn’t think of it till I looked for a diagram, but yeah, it’s exactly how active noise cancellation works