I have a bunch of expensive headphones (Bose QC2, multiple inner ear), and the best solution I've found costs $28 and allows me to listen to music comfortably on a Mac at 0.5 tick! I use a pair of earphones[0] covered by industrial ear muffs[1]. For comfort reasons, it's important that the earphones are not pressured by the surrounding ear muffs. I haven't found any inner ear headphones that meet this constraint. Som…
30dB isolation is about what is claimed from some DJ style headphones. I use a pair of old BeyerDynamics that claim 20dB isolation and that seems a good compromise between peripheral awareness and isolation for my particular setting.