There is a free App for decibals on an Iphone if you have one or know someone. (RPM too) Then you could experiment to see if it fits in the rules. Radio Shack used to carry a fairly cheap decibal meter. Of course we have no more Radio Shacks around, but the other place may find them, or Ebay. I found the big chain saw type IMAC motors were the loudest, when I lived about a mile from the field. I think the lower pitch noise carries, like elephants. I know the other neighbors near me did not like the noise at all, but were Mennonites, and did not complain much. It did not really bother me at a mile, but you could hear it for sure, and I would guess a quiet day in the country with that noise all and every day could bother you after a while. I could not hear the .60 size ones at all, they flew a bit lower too. Actually if I heard a noise, I would go over and fly, if I had stuff ready.
Last edited by aspeed; 10-20-2014 at 01:20 PM.