Originally Posted by altimiters
Something to do with active noise canceling that it uses a higher pitch frequency to block out the ambient noise. This in turn slowly sends you deaf first in the higher range.
That ain't the way ANR works. It does not mask the noise, nor is it just merely causing the noise to not be perceived. It physically makes the noise (mostly) cease to exist within the protected area. And it certainly doesn't do it by using a higher frequency. The entire process is dependent on using the identical frequency as the noise to be eliminated.