Excluding Etymotics which isolate better than a lot of dedicated hearing protection, my DT770s isolate better than any head/earphone I’ve ever owned, but with stock pads I just had a short phone conversation without taking them off my head. If that phone call was any longer I’d have taken my DTs off for comfort, not an inability to hear.
Etymotics are great if you wanna listen to a podcast while mowing the lawn or at a private shooting range (please don’t do that shit around other people and you should still wear over ear hearing protection. If I can find the article explaining why you should always wear over ear hearing protection I’ll link it) but they still sound mediocre IMO and are easily the least comfortable IEMs I’ve ever owned. I suspect that my DTs will perform well enough to drown out the world with classical instead of metal or EDM when my Dekoni leather pads show up but it’d be nice to have some sort of list to compare to.
Sound isolation seems like it would be a relatively easy thing to measure and quantify. I’m reasonably certain that every reputable company that makes hearing protection for use with firearms, loud equipment, by DJs, etc, already does this in a scientific way, but outside of SEO garbage I can’t seem to find a list for music enthusiast and what different people find acceptable levels of isolation seems to vary.
I’d imagine a list of the best and worst isolating headphones in various categories that’s more granular than “buy Etymotics if you work with power tools” and “buy bone conducting if you need a NY state compliant driving headset” would be useful to a lot of folks.