Noise cancelling headphones. My work requires a lot of air travel and I have trouble with loud noises in general. I bought a pair a year or so ago for just under $70 and it's as good or better than the more expensive one ($150 refurbished) I got in 2017. It also has a mode to let the external sound through if someone is trying to talk to you.
It really does eliminate some of the annoyance of air travel.