Here's another related one that always bothers me: When you say something's loudness in decibels, you also need to specify a measurement distance.

The author of this article even accidentally makes this omission:

> It’s 94 dB, roughly the loudness of a gas-powered lawnmower

And that distance is very important; the actual sound pressure measured is proportional to distance^2. So for a lawnmower measuring 94dB, let's say we assume that we're measuring at 1m. At 2m away, the sound is actually 91dB.

And don't get me started about the fact that a halving in power is 3dB, that's just wacky. I wish we used base 2.

> And that distance is very important; the actual sound pressure measured is proportional to distance^2.

While we're sniping nerds, the inverse square law only applies in the far field (which is tautologically "far enough away for the source to behave as a point source and follow the inverse square law"). That's probably a good bit further than 1m for a lawnmower in the physical world. For loudpseakers you have to be about 2m away before the inverse square law kicks in, unless they've been designed to operate as line sources which decay linearly for a very long distance. For loud sound sources near barriers like the ground they behave like half point sources, which will eventually act like point sources but there's a good bit of distance before it is really measurable.