I have discovered what I call the Hatred Frequency™. I call it that, because if you hear it long enough, it will cause you to hate everything, and eventually slip into an inescapable murderous rage. I’m not sure how long that process takes, because I have no experimental data, but I was definitely slipping into insanity by the end.
Said frequency is produced by some component of 2000 manufacture year A319s when taxiing. If you are stuck in the middle of the tarmac for 10 minutes, then you get the joy of hearing the Hatred Frequency™ for that period, plus more!
Normally I can block out repeated background noise, but this was just so grating that I literally stuck my fingers in my ears. Yes mother, I know – I should never put anything smaller than a football in my ear.