May 28, 2011
Selective Hearing Linked To Focus, Concentration
Is it really possible for people with perfectly normal hearing to become deaf to the world around them when they are concentrating on another subject? New research funded by the Wellcome Trust suggests it is in fact possible.
The new study, published in the journal "Attention, Perception, & Psychophysics', suggests that focusing heavily on a task results in the experience of deafness to other sounds within earshot. Researchers at University College London (UCL) demonstrate this phenomenon -- called "inattentional deafness" -- for the first time.
"Inattentional deafness is a common everyday experience," explains Professor Nilli Lavie from the Institute of Cognitive Neuroscience at UCL. "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, along with one of her PhD students, James Macdonald, devised a series of experiments designed to test for inattentional deafness. More than a hundred participants were involved in the experiments. The subjects were asked to perform tasks on a computer involving a series of shapes. Tasks varied from very simple to difficult.
Participants wore headphones while carrying out the tasks being told by researchers that they were to aid their concentration levels. At some point during the tasks a tone was played unexpectedly through the headphones. At this point in the experiment, the tasks were stopped and researchers asked if the participants had heard this sound.
During the simple tasks where little concentration is needed, about 2 in ten participants missed the tone. However, when focusing on a more difficult task, about 8 in ten of the participants failed to pick up the sound.
The researchers believe that when peoples' attention is fully taken by a purely visual task the result is limited capability in processing sounds.
It is already known that people similarly experience "inattentional blindness" when engrossed in a task that takes up all of their attentional capacity. An example of attentional blindness is the Invisible Gorilla Test, where observers engrossed in a basketball game fail to observe a man in a gorilla suit walk past.
The new research shows that being fully engrossed in difficult tasks makes us blind and deaf to other sources.
Inattentional deafness is "a common everyday experience," Lavie told the Telegraph.
"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," said Lavie.
Inattentional deafness could be a real world hazard. It has been well documented that a large number of accidents have occurred due to a driver's inattention and this new research suggests inattentional deafness is yet another contributing factor.
The researchers did not look at whether men or women were more prone to inattentional deafness.
"From my own personal experience, I suspect that men are more susceptible," Lavie laughed. "But that's not based on any scientific knowledge," she noted.
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