New research has learned that inordinate concentration on a task can literally make an individual deaf to the world around them.
Investigators believe this deafness, when attention is fully taken by a purely visual task, is the result of our senses of seeing and hearing sharing a limited processing capacity.
The behavior, termed “inattentional deafness” is the subject of a new study published in the journal Attention, Perception, & Psychophysics.
“Inattentional deafness is a common everyday experience,” said co-author Nilli Lavie, Ph.D., University College London.
“For example, when engrossed in a good book or even a captivating newspaper article, we may fail to hear the train driver’s announcement and miss our stop, or if we’re texting whilst walking, we may fail to hear a car approaching and attempt to cross the road without looking.”
Lavie and her team devised a series of experiments designed to test for inattentional deafness. In these experiments, over a hundred participants performed tasks on a computer involving a series of cross shapes.
Some tasks were easy, asking the participants to distinguish a clear color difference between the cross arms. Others were much more difficult, involving distinguishing subtle length differences between the cross arms.
Participants wore headphones while carrying out the tasks and were told these were to aid their concentration. At some point during the task performance a tone was played unexpectedly through the headphones. At this point, immediately after the sound was played, the experiment was stopped and the participants asked if they had heard this sound.
For the easy tasks requiring relatively little concentration — such as judging the respective colors of the arms – – around two in 10 participants missed the tone. However, when focusing on the more difficult task – identifying which of the two arms was the longest – eight out of 10 participants failed to notice the tone.
It is already known that people similarly experience “inattentional blindness” when engrossed in a task that takes up all of their attentional capacity; for example, the famous Invisible Gorilla Test, where observers engrossed in a basketball game fail to observe a man in a gorilla suit walking past.
The new research now shows that being engrossed in a difficult task makes us blind and deaf to other sources of information.
“Hearing is often thought to have evolved as an early warning system that does not depend on attention, yet our work shows that if our attention is taken elsewhere, we can be effectively deaf to the world around us,” Lavie said.
“In our task, most people noticed the sound if the task being performed was easy and did not demand their full concentration. However, when the task was harder they experienced deafness to the very same sound.”
Other examples or real world situations include inattentional deafness while driving. It is well-documented that a large number of accidents are caused by a driver’s inattention, and this new research suggests inattentional deafness is yet another contributing factor.
For example, although emergency vehicle sirens are designed to be too loud to ignore, other sounds – such as a truck beeping while in reverse, a cyclist’s bell or a scooter horn – may be missed by a driver focusing intently on some interesting visual information such as a roadside billboard, the ad on the back of the bus in front or the map on a GPS device.
Source: Wellcome Trust