CBE w/no or least drone?

Originally Posted by chii370

I guess if your hearings been damaged that much then yeah, your right. Generally speaking 99% of humans hear in or around the exact same freq range. Otherwise there wouldnt be a thing called a hearing test, it would give completely inaccurate unacceptable results every single time for each different person. Its subjective to a point of TOLLERANCE is more to the point. How high is your "annoying" level. But common sense comes into play too. We are talking about if you can hear it or not, not if it bothers u. Drone is a physical provable occurance that could be monitored if one so chose. Aka how much NOISE its making in cabin at speed in a constant tone. If you cant hear that...i dont know what to say.