Pedestrians wearing headphones at risk

The number of US pedestrians who have been killed or badly injured while wearing headphones has tripled in six years, ABC reports referring to a new study.

The researchers, led by Richard Lichenstein of the University of Maryland Hospital for Children in Baltimore, trawled through various sets of data to identify accidents that involved pedestrians wearing iPods, MP3 players and other musical devices. It did not include mobile phones.

They found that the annual tally rose from 16 in 2004 to 47 in 2011, bringing the total of cases to 116 over this period.

"Everybody is aware of the risk of cell phones and texting in automobiles, but I see more and more teens distracted with the latest devices and headphones in their ears," says Lichenstein.

"Unfortunately as we make more and more enticing devices, the risk of injury from distraction and blocking out other sounds increases."

More than half of the incidents involved pedestrians who were run down by trains, while two-thirds of the victims were males and under the age of 30 years.

The research, published in the journal Injury Prevention, warns of "inattentional blindness" when wearing headphones, meaning a distraction that lowers the resources the brain devotes to external stimuli.

"Whenever you're running or walking around listening to music you're allocating some of your brain to listening to that music and the other part to the activity you are doing. You really can't do both of those activities at 100 per cent," says Lichenstein.

The researchers add that the distraction is intensified by sensory deprivation, so that the pedestrian's ability to hear an oncoming train or car is masked by the sounds produced by the headphones.