Ушная сера means earwax, and a glob of that stuff that impedes your hearing is called ушная пробка “an ear clog.” Often the Russians will simply leave out the ушная part and just say сера or пробка. I really couldn't care less about this phrase, but the other day one of my students was given an assignment to write a bunch of phrases starting with «спасибо за» “thanks for,” and he came up with:

The phrase is grammatically perfect, so I can't take off any points. But by God, for that kind of disrespectful composition, I'm surely going to stiff him on his final grade, подлец the bum.