The number of headphone-wearing pedestrians who have been seriously injured or killed near roadways and railways has tripled since 2004, according to a U.S. study.

University of Maryland researchers found that people were often hit by vehicles because their music blocked alerting sounds from incoming cars or trains and lead to deaths in nearly three-quarters of cases of headphone causing accident injuries.

"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," lead author Dr. Richard Lichenstein said in a statement on Monday. "Unfortunately, as we make more and more enticing devices, the risk of injury from distraction and blocking out other sounds increases."

Researchers said that 70 percent of the 116 accident cases from 2004 to 2011 resulted in death to the pedestrian, and about 68 percent of the victims were male, and 67 percent of cases involved victims who were under the age of 30. Researchers also reported that more than a half of moving vehicles involved in the accidents were trains at 55 percent, and nearly a third of the vehicles reported sounding warning horns prior to the crash at 29 percent.

Researchers said that the increased rate of incidents involving headphone use correlated with the rising popularity of headphone use and auditory technologies.

Lichenstein noted that the two likely phenomena associated with these types of injuries and deaths are distraction and sensory deprivation.

Researchers explained that the distraction is caused by the use of electronic devices causing “inattentional blindness” where multiple stimuli divide the brain’s mental resource allocation. The distraction is then magnified by sensory deprivation when the pedestrian’s ability to hear a train or car warning alert is masked by sounds produced from the headphones.

"As a pediatric emergency physician and someone interested in safety and prevention I saw this as an opportunity to -- at minimum -- alert parents of teens and young adults of the potential risk of wearing headphones where moving vehicles are present," Lichenstein recommended.

The study was published in the journal Injury Prevention on Tuesday.