Eyes hard at work can make ears go temporarily deaf

There’s only so much brainpower to go around, and when the eyes hog it all, the ears suffer.

When challenged with a tough visual task, people are less likely to perceive a tone, scientists report in the Dec. 9 Journal of Neuroscience. The results help explain what parents of screen-obsessed teenagers already know.

For the study, people heard a tone while searching for a letter on a computer screen. When the letter was easy to find, participants were pretty good at identifying a tone. But when the search got harder, people were less likely to report hearing the sound, a phenomenon called inattentional deafness.

Neural responses to the tone were blunted when people worked on a hard visual task, but not when the visual task was easy, researchers found. The results suggest that perceptual overload can jump between senses.