Can't say anything about this instance without being there yourself, but noise pollution is a real problem. The cited decibel numbers are useless too since it doesn't specify at which distance. Could be a meter from the facility or it could be at the house. It's not just about decibels though, different noises are perceived differently and that's really what matters.

Frankly, that's not a bad idea, do that instead if it's an option. If the noise really is bad, quite deviously really, the value of the house has been reduced. So it's cheaper now. If the mining goes belly up later thus stopping the noise, you can at least sell the house at a higher price.