Headphones

Live sound engineer here. Im at 5 concerts a week. My best recommendation is Sensaphonics with a -9~ db plug. They are molded. You go to a ear doctor and the create a mold of your ear which you then send to the company. My doc did it for free since Im in the industry and threw in an ear test as well which I loved. These are the plugs most professional touring guys have hanging from their belts.

The cheap option I would recommend is the Etymotic research ones. Pretty good response off those. I keep a pair in my work case as back up.

I purchased molded earplugs that came with inserts for both -5db and -30db protection. Ran me like ~$150 total I think. Sorry but it was a few years ago.

Either way I went to a local ENT Doctor and got my ears fitted, and receive my plugs a week or two later. They were listed as “musician’s plugs” and have a very flat response. Or maybe it’s a curved response. I’m not sure how it should be said. What I’m getting at is the attenuated sound I hear is very true to what I would hear without them, just quieter. One of the best purchases I’ve ever made.

One of the best cheap (non-custom) options is the Alpine MusicSafe Pro (~25€).
If you wanna go for a custom hearing protection you're quickly into 3 figures. Here in Germany there are some vendors for custom stuff where you could get some "no name" custom or some brand stuff like the Alpine PartyPlug Custom for ~200€.
But with all custom stuff the price heavily depends on what exactly you want, from which brand and where you are ordering it.

In general I would recommend getting the cheap non-custom option, see if it works for you and if not you can still cash out for some custom ones. 25€ is not that big of an investment compared to the price of a custom set.

I’ve been using the 20$ musician earplugs you find on Amazon. They’re cheap enough that If I loose them it’s no big deal and they have a natural flat freq attenuation. They claim something like 20db

I have sensitive hearing, and while I don't go to many concerts anymore, I'll often put in in my earpods at the movies, for example.

Some great recommendations from industry folks already.

But if you're not frequently in such high volume environments and you want something for the occasional concert you may want to start with cheaper options.

Don't take your hearing for granted - hearing loss is disabling and isolating - whatever you choose it is important to have something comfortable and convenient to carry that you will use and is up to the demands of the environment you'll be using them in.

I have Eardial for concerts (1-2/yr if that these days). ~$30. They are very comfortable, fit well (even though most earbuds pop out of my ears), easy to clean, and have a small clip on carrying container. Manufacturer says 11db reduction. Great for music but conversation in crowds is a little muffled. I've had them for a few years (prepandemic) and there's no sign of deterioration since they are lightly and gently used.