A pair of high fidelity earplugs (aka concert earplugs or filtering earplugs). You can get a good non-custom pair for $15–$40, and that’ll work well for the average person for a long time.
They’re excellent for live music, airplanes, and anytime you want the world to be quieter but still need to be able to understand speech. And for music specifically, they can bring the volume level down just enough to be safe without muffling the sound like traditional foam earplugs do. Protect your hearing, kids!
I know it’s way more expensive, but the last gig I went to, I used my AirPods Pro in transparency mode, and it reduced the sound down from an insane ~110db to peaks of 90! Definitely worth protecting your ears.
Yeah, I can't stand losing the high frequencies and overall feel of the music with "musician's" earplugs. How anyone other than a drummer plays with them and is satisfied is beyond me. I have some Etymotics just sitting here.
For anyone reading this, I definitely recommend Earasers. I have spent the better part of my life around really loud music things, especially because of my job. These things work wonders and are incredibly comfortable and low profile
Even regular earplugs at a loud concert work amazingly well for me. I can still hear conversation (people yelling over the music) but the deafening volume of the concert is brought down to acceptable levels.
I don't understand why concerts are so loud. They're just...so, so fucking loud...