Having just seen a virtually silent drone on a TED talk, I'm wondering: where exactly does the noise from a Mavic Air (which I wish was a little quieter) come from? Is it the motors? The sound of the props cutting through the air? Some combination of the two? What would be entailed -- and what might be compromised -- by making the thing a lot quieter? Would adding some kind of soundproofing around the motors do it? Changing the shape of the props?