In a noisy environment, you still hear the words of the interlocutor, if you want, and the remaining sounds in this time relegated to the background. Researchers at Columbia University have tried to find out how the brain copes with this problem. It turns out it's pretty simple.
Nowadays there is a widespread procedure - patients to implant electrodes in the brain before surgery to determine what area of the brain responsible for the seizures. Six patients with a diagnosis of "epilepsy" and the electrodes in the brain for a couple of days before surgery were asked to watch two videos on the average duration of ten seconds at a time. Each video man told a story, and the subjects had to concentrate on one of them.
It turned out that people hear at the same time, both the story, that is, both the video cause in the brain activity. However, at the sound, which was necessary to listen, to start activity lower frontal cortex responsible for speech perception and language. The longer had to concentrate on other people's words, the stronger the activity of this area of the brain: the longer you listen to the words of the interlocutor in the midst of the noise, the better you hear it.