Wax can block your ear canals, and it can literally disable hearing aids. We frequently have customers return their ZVOX hearing aids saying "they stopped working." But when we examine them we find that the ear domes are clogged with ear wax! (And the hearing aids were working just fine.)
Unless you've taken a long airplane flight while wearing good noise cancelling headphones, you can't understand why they are so important. That's because your brain will trick you. It will convince you the jet engines aren't THAT loud.
But they are.