I think they just use the same type of noise protection headphones used by people working along/near the runway of an airport to cancel all the background noise, then an in-ear earphones (because if you use the regular earphones, the outer parts of it would be squashed in between the headphones causing it to be uncomfortable to your earlobes
I find them very comfortable to use with glasses, and I can fit Sennheiser https://www.amazon.ca/Sennheiser-II-Precision-Enhanced-Earbuds/dp/B001EZYMF4 very comfortably underneath, if I am careful about how I rotate the earphone and feed out the wire. These earphones break super easily though, so I wouldn't use them walking around, but they're pretty safe for use at home. The wire tends to short out if you wear them in your jeans pocket. The only reason I recommend it at all is that it keeps a very low profile in your ear, so it is the most comfortable to wear in combination with hearing protection.
This is a very practical solution if you need quiet while working, but they do stick out like mickey mouse ears and make you look like a dork. Unlike most hearing protection though, they're really comfortable. I would guess if you get what the progamers use, they may not be that comfortable. The players only have to put up with them for a few games on match day. If you are looking for a solution for work, you might need to choose more carefully.