Selective hearing is not just the affliction of teenagers avoiding parental summons. Turns out the human brain is wired to tune in to just one sound at a time, according to UCSF researchers who published their findings in Nature last week. 

Some little grey cells right behind our ear actually filter out some sounds in our environment, allowing us to focus on what is most important to us. At a restaurant, this means we can tune out the clinking of glasses and background music to hear what is being said directly to us. In the wild, it means we can hear the sound of an approaching predator over the sound of wind in the trees and birds chirping.

It is just more evidence that humans really aren't built to multitask, despite the claims of most us that we can, in fact, pay attention to more than one thing. Right now, I'm typing this post with the television on -- and what I'm actually doing, according to scientists, is switching my attention rapidly between my writing and the plot of Criminal Minds. And not focusing completely on either one.

It's a relief, actually, to read that only 2.5 percent of us can actually multitask and to realize that I am not in that small group of super-taskers. I can quit telling myself that I need to get better at multitasking -- which is probably never going to happen -- and finally heed my parents' advice to turn the TV off while I'm doing my homework.