BALTIMORE, Jan. 17 (UPI) -- The number of serious injuries of those wearing headphones with an iPod or MP3 player tripled in the United States from 2004 to 2011, researchers say.
Dr. Richard Lichenstein and colleagues from the University of Maryland School of Medicine analyzed data from the U.S. National Electronic Injury Surveillance System, the U.S. Consumer Product Safety Commission, Google news archives and a university research database on injuries and deaths among pedestrians wearing headphones.
However, all U.S. injuries involving cell phones, including hands-free devices, were excluded, Lichenstein said.
The study, published online in the journal Injury Prevention, found during the six-year study period there were a total of 116 cases, 16 of which occurred in 2004/2005. By 2010/2011, this figure rose to 47. Seventy percent of the accidents were fatal, the study said.
The average age of the victims was 21 and 55 percent were struck by trains, about two-thirds were male and two-thirds were age 30 and under.
Twenty-nine percent said onlookers mentioned horns or sirens sounded before the individual was hit.
The study authors said distraction and sensory deprivation both play a role in tuning out external sounds -- coined "inattentional blindness" -- which essentially lowers the resources the brain devotes to external stimuli.