My band uses Shure IEMs onstage, except our singer.
the IEMs do a good job of blocking stage noise, and you don't have to have a loud volume mix in your ears, you can hear everything great at a decent level. I like it much better than monitors.
When practicing in the studio, I wear StudioKans Isolation headphones. You can also send audio signal to these.
Haven't tried the foam or plastic earplugs, I usually want access to some kind of signal while playing. Guess that comes from using Edrums a lot.
I use regular isolation headphones which cut about 20 dB for practice, and if I want to use some sound source(metronome, playalong tracks) I use Vic Firth's SIH1 headphones. They cut about 22 dBs and are OK. Just plug them to a laptop and there I have an equalizer so I can get the sound that i want on them.
I didn't wear any hearing protection for about the first 25 years of my playing, and now I really regret it. I've lost about 50% of my hearing in each ear, and now I swear by earplugs. I have a nice custom-made set of clear ones that cut everything down by about 50dB. I also invested in a Butt-Kicker for my throne so I can feel the bass.
Take it from someone who has lived it: WEAR HEARING PROTECTION. Your ears will thank you for it.
I use the PELTOR ear-protectors. My model is designed for woodcutting that makes it high frequencies killer. When I play alone everything is in perfect order and the headphones improve the sound of drums (in some way), but when I play with a band it's quite hard to hear a guitar 'cause its deafened by low freq.
I use the Vic Firth headphones myself, since I play very loud, I must protect what's left of my hearing of 30 years bashing drums and playing in bands to which the guitarist would turn their amps up to 10.
The Headphones have come in handy. Before then, I would get headaches after 10 minites of drum practice. And under headphones I can still make out every tone from the drums, cymbals and the other guys that I jammed with. I definly recommend some type of hearing protection, it'll prolong your music career ;-) :-D