and a pair of closed headphones(noise-cancelling by definition sucks) like audio technica 50's or the venerable old studio monitor sony's and senn hd280's. just low-impedance shit that by virtue of being closed keep noise out, something like a grado 325i's great but doesn't shut outside noise out or keep your noise from emanating out. high-end earbuds are fine if you're into sealing shit into your ear canal perfectly then blasting down the thing until your hearing's a disaster. good for the money, there are full-sized low-impedance headphones for a little more of it that are comfortable or reproduce shit MUCH better than i can hear it.
since a few years the Shure SE530's changed my life and cured my sexual dysfunction, a gym packed with 300+ feels like you're alone there and you can really focus without the skull-hammeringly dull conversations and random noises. someone can stand two feet in front of you saying words and its just two lips moving like hallucinating katy perry on mute. first time i tried them;
(stunned silence)
(more stunned silence with rapid heartbeat)
(body hits a chair and then the floor)