 Have you ever been someplace noisy with a friend, maybe a bar or a concert, and they said something to you that you didn't understand? Maybe it sounded something like this. It was pretty hard to understand, right? But what if we heard a clean version of that sound? If this doesn't work, it'll be really embarrassing. You can understand it easily. So what would happen if we replayed the garbled version again? I'll bet you could understand it this time. The words just popped out at you. So why is this? We conducted the same experiment in order to answer this question. The first time that we played the garbled sentence, we didn't see very much activity in parts of the subject's brain that are associated with sound or understanding speech. The second time that they heard the garbled sentence after they had heard the clean sentence, we saw a very different pattern emerge. What we found was that your brain actually changes the way that it focuses on different parts of the sound. This allows it to understand this garbled speech sentence even though it couldn't understand it the first time. This is really important because one of the biggest tasks that your brain has is in filtering out all of the noise that's present in the world around it. And what we showed was evidence that your brain is using its previous experience with sound in order to make this happen. By understanding the ways in which our brain filters out noise in the world, we hope to be able to create devices that help people with speech and hearing impediments accomplish the same thing. It will be really embarrassing.