Inverse square law is proportional, so the distance isn't fixed. It depends on the base sphere of the original measurement, which can be quite large. If the size of the data center property is 100m and the flux at the property line is 70dB, it's only 1/4'd at a doubling of the radius, 50m away. So that only attenuates to ~65dB.
It's also not a uniform medium. Sound gets reflected by houses, the ground, resonance, so it can constructively interfere and have a extra few times the expected amplitude. This can make the sound quaver and become really annoying, too.
It's also not a uniform medium. Sound gets reflected by houses, the ground, resonance, so it can constructively interfere and have a extra few times the expected amplitude. This can make the sound quaver and become really annoying, too.