[everybodyknows]

You may find it hard to find audiophile headphones that suppress voices adequately. I had better results with ear muffs from the local hardware store intended for leaf-blowers. Get the biggest, ugliest ones you can find.

[Arizhel]

I have some of these that I use for lawn work, which are designed for shooting guns. They isolate sound pretty well, but they're also not terribly comfortable. They're OK for driving around on my lawn mower for 30 minutes, but there's no way in hell I'd wear them for 8 hours.

[pklausler]

Good idea, especially if they are big enough to fit over Bluetooth earphones (e.g. AirPods).