The IJMC rules are still there under "F4J Rules" as they have always been. Did you have problems finding them?
Davie,
I found the rules but the noise test has been completely removed. I think it was rule 3?
I think I will offer a comparison test. I will ask for a prop model that has passed the ground test to be re-tested in the air. I will then offer to have my jet tested in the air and see what happens.
Hopefully it won't come to this.