Now I have already turned my PC speakers loud to drown out the noise. But that is in turn only possible if you do stupid work and have to think anything. Headphones also were not successful, as the noise penetrated still by when no music was (and with music: see above).
So now I have in the meantime also snacked earplugs and Co., with moderate success. Some are not positioned correctly, the other pressing with time. But now I am happy with the Alpine Sleep Soft: this damp very well (as it verhällt with the filter, I can not say exactly, but I can still hear discreetly the clatter of fingers on the keyboard and otherwise really only my own nasal breathing.) and they are also quite comfortable. I've already had two days in a row the whole afternoon in the ear and no pain etc. get it. For me a wonderful blessing to finally concentrate on work again !!