Who' that thing called?

ferluci94
Sat, 14 Aug 2010 04:21:30 +0000

Hi, everybody.
I’m from Ukraine, but am currently studying and living in Boston.
So I’ve got a question.
How are those small things on noise-isolating headphones, that make them isolate the noise called?
I’ve just lost mine and it turns out to be hard without hard rock, while in bus.
Thanks :)