The concept of this is quite similar to that of
Beer Goggles. It is not related to
female genitalia, at least not directly.
There is one girl who sometimes hangs around with me and my friends who is EXTREMELY talkative. She isn't too bad looking, and she means well, but she just won't shut up. It is unfortunately almost impossible to have a conversation, or at least a two sided one, with this person. She loves telling stories about high school, stories about her roommate, stories about anything... They are very long-winded and full of details and the names of people no one else knows.
At times it can be difficult to hang out with this person. However, we have noticed that while we are drunk, the problem is not even noticable. I don't know if it's because we can't hear her, or if it's because when you're drunk stuff seems a lot more intresting than it is. But whatever the case, it is possible to have interesting, meaningful conversations with this person after having a few beers.
Someone decided that similar to beer goggles, beermuffs must cover your ears when you are drunk and weed out annoying or unpleasant comments. In this particular case, the effect is remarkable.