I realize this thread was started over a month ago by a one-time poster, but I'm putting this here in the hopes that it can help some other poor soul out there...
I've also suffered from misophonia for years. It can truly suck. There's nothing quite like feeling rage toward my wife because she's eating... Or breathing. Oof. I was once in the food court by my job and there was somebody slurping noodles and I seriously thought I was going to punch the guy in his face. The rage was strong!
Dulalala is right, depending on your triggers. ANC headphones do a good job of blocking constant noises of a certain frequency, but not sudden random noises. If droning noise is one of your triggers (makes me more anxious than rageful), they might work. But if your triggers are chewing, babies crying, snack bags rustling (one of the worst for me), other sounds that aren't constant, then ANC might not do much.
Simple foam earplugs or IEMs (In Ear Monitors-- earphones that you insert into your ears like earplugs) might work better for you. The problem with IEMs or earplugs is that eating with them in is a whole new exercise in repulsive noises. Not rage-inducing (for me), but gross. Really gross.
Good luck with figuring it all out. People that have never experienced misophonia just don't understand and often think you're just overreacting, or something... Which in itself is infuriating.
You could also try therapy for it (I think CBT is most common... Don't quote me on that). It is almost entirely psychological, so blocking the noise is really just putting a band-aid on it.
Don't give up hope! I actually think I've got mine beat! I've been on Saint John's Wort for the last few months and haven't experienced a single trigger since (well, maybe one or two, but compared to the daily or hourly triggers I had before it's nothing)! Woot woot! I'm hoping beyond hope that it doesn't come back and that I can one day stop with the SJW.
Good luck! I feel your pain!