The Environmental and Energy Study Institute (EESI), a non-profit organization, said that high- and low-frequency sounds emitted by these industrial sites can be heard and felt for hundreds of feet in surrounding areas, with noise levels reaching as high as 96dB for 24 hours a day and seven days a week.
It says “these industrial sites” so it’s making a generalization, it says “as high as” so that’s presumably the maximum they measured at one of those many sites. They also talk about high and low frequency sound, so it may not be the infrasound that is “loud” but the high frequency sound, which doesn’t as easily travel through the ground, etc.
Because sound tends to follow an inverse square law, if they measured that 96 dB at 100m from the sound’s source, it could be just 2% of that level at 800m away.
So, that “96 dB” figure needs to be taken with a grain of salt. The figure as actually measured in some person’s home might be a tiny fraction of that amount.
Again, it doesn’t mean there’s no problem, just that it needs some further investigation.
What level is that?
The article mentions 96 dB for 24 hours a day
It says “these industrial sites” so it’s making a generalization, it says “as high as” so that’s presumably the maximum they measured at one of those many sites. They also talk about high and low frequency sound, so it may not be the infrasound that is “loud” but the high frequency sound, which doesn’t as easily travel through the ground, etc.
Because sound tends to follow an inverse square law, if they measured that 96 dB at 100m from the sound’s source, it could be just 2% of that level at 800m away.
So, that “96 dB” figure needs to be taken with a grain of salt. The figure as actually measured in some person’s home might be a tiny fraction of that amount.
Again, it doesn’t mean there’s no problem, just that it needs some further investigation.