A new U.S. study looking at injuries and deaths among pedestrians wearing headphones finds that trains were involved in more than half of the cases identified.
The researchers studied databases for reports from 2004 to 2011 of accidents involving people wearing headphones.
Their study, published in the journal Injury Prevention, on Tuesday found 116 reports of death or injury of pedestrians wearing headphones, of which 81 were fatal. During the study period, the number of cases tripled.
The researchers suggest that the use of headphones with handheld devices may pose a safety risk to pedestrians, especially in environments with moving vehicles.
Fifty-five per cent of the accidents the researchers identified involved trains, and the majority of victims were male and under the age of 30.
Almost nine out of 10 cases were in urban areas, and almost three in 10 cases mentioned that a warning was sounded before the crash.
The researchers acknowledged a number of limitations to their research, however. For instance, it relied on media reporting "which likely over-publishes tragic events but vastly under-publishes non-fatal cases."
And factors other than the use of headphones — such as suicidal intentions, substance abuse or mental illness — may have played a role in some of the pedestrian injuries and fatalities. They suggested more study is needed.
"The use of cellphones and MP3 players is increasing. The risks posed in use of these devices by drivers are well documented, but little is known about the association between headphone use and pedestrian injury," wrote the researchers, based at the University of Maryland.
"The danger in using headphones as a pedestrian may be explained by two phenomena: auditory masking of outside stimuli (environmental isolation) and distraction (inattentional blindness)."
The study involved searches of the National Electronic Injury Surveillance System, U.S. Consumer Product Safety Commission, Google News Archives and Westlaw Campus Research databases.