Who' that thing called?

<p>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 :)</p>

<p>mistake in the topic name => What’s</p>

<p>Do you mean the tips on IEMs?
Do your headphones look like this?
<a href=“http://upload.wikimedia.org/wikipedia/commons/0/0f/InEarMonitors.jpg[/url]”>http://upload.wikimedia.org/wikipedia/commons/0/0f/InEarMonitors.jpg&lt;/a&gt;
or
<a href=“http://img.tomshardware.com/us/2007/03/14/10_earphones_under_100_dollars/sennheiser_cx300.jpg[/url]”>http://img.tomshardware.com/us/2007/03/14/10_earphones_under_100_dollars/sennheiser_cx300.jpg&lt;/a&gt;&lt;/p&gt;

<p>Those tips, might be found at a dollar store, unless you want say, top notch foam tips, like comply tips, which can be found at Radioshack. If you don’t have really expensive headphones, it might be more worthwhile to just buy another pair.</p>