I have started to notice it recently , although thus far it is not too much of a problem/distraction/nuisance. I suppose it was only to be expected, as I spent a lot of time in the Navy close to jet engines (without wearing ear-defenders ) and watching 4.5 inch live anti-aircraft firings from the funnel-deck of HMS Eagle ,and firing THOUSANDS of rounds of .303 rifle ammunition over a period of 11 years , again without ear protectors. Oh well, never mind ; must go now, I think there's someone at the front door !!