Your better half is engrossed in the latest episode of Homeland when you ask for help cleaning up the kitchen.
When she doesn't respond, you assume she's conveniently ignoring you. But in reality she might not even hear you.
The ability to process sound and the ability to process sight share the same part of the brain, suggests new research. So when a person focuses on a complex visual task - say, determining if he is or isn't a bad guy in a tense but wordless TV scene – they can become deaf to other sounds around them.
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Anyone who's been staring at an interesting billboard not seen an approaching car, or who's been reading a page-turner and not heard his child arrive home from school, knows this anecdotally.
And previous research has suggested that the reverse is also true: when people switch to pay attention to sounds, they lose the ability focus on what's in front of them. Think of the driver who takes a cell phone call and starts swerving.
Now, by using brain imaging, researchers have uncovered the extent of this "inattentional deafness," or how intensive visuals rob us of the ability to hear.
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"When volunteers were performing demanding visual task, they were unable to hear sounds that they would normally hear," study coauthor Dr. Maria Chait said in a release. "The brain scans showed that people were not only ignoring or filtering out the sounds, they were not actually hearing them in the first place."
This is great news for spouses the world over who've long pleaded, "But I really didn't hear you!" But it also has broader implications. Doctors in noisy operating rooms may benefit by being aware of this phenomenon, for example.
Pedestrians who text and walk should take heed, too.
"They're prone to inattentional deafness," coauthor Professor Nilli Lavie said in the release. "Loud sounds such as sirens and horns will be loud enough to get through, but quieter sounds like bicycle bells or car engines are likely to go unheard."