http://www.digitaljournal.com/a-and-e/gaming/12-percent-of-gamers-have-hallucinations-after-long-play-sessions/article/395326

12% of gamers have hallucinations after long play sessions

Posted Aug 6, 2014 by Walter McDaniel
According to recent studies around 12 percent of players hear sounds from their games after playing. Hallucinations include hearing bullets, explosions and whispering voices.
What games study participants played were not a large factor in the study. Across the board ones who...
What games study participants played were not a large factor in the study. Across the board ones who played longer were more likely to hallucinate.
Walter McDaniel, Supergiant Games
Researchers surveyed gamers who played over long periods of time. After playing for various amounts of time study members reported findings back to the researchers at Nottingham Trent University. Many reported hearing everything from weapons to orders being shouted by characters from the game. Other information states that the sounds were often caused by seeing similar incidents to those in the game, such as having someone yell at them or seeing a vehicle.
You can read the findings for yourself here which collected 192 sets of data from 155 gamers. Findings were first published there and on the school's website which led many other sites to pick the story up.
Auditory hallucinations are a highly studied, if not fully understood, aspect of psychology. Causes vary from chemical imbalances, to trauma and even simple mental stress. Due to the fact that so many things could be causing it researchers will have to do more work on the subject to find the cause. It is even possible that the cause varies from player to player.
Authorities such as those in the American Academy of Pediatrics have stated for some time that gaming leads to mental illness. Another study also showed that gaming can cause visual hallucinations as well. As such these new findings may give them more evidence for their case.
As you might expect many of those who play games do not agree with this assertion. Recent findings even support that idea that playing video games less than an hour a day leads to better-adjusted children. Previous claims about video games and violence have been proven false by science so the debate continues.