New York, 19 Jan

People who play video games are at risk of damaging their hearing due to potentially unsafe sound levels, a study has found. The new review suggests that gamers play for long periods of time with the volume turned up, beyond safe limits.

It says this could contribute to irreversible hearing loss or tinnitus, a constant ringing in the ears. The paper, published in BMJ Public Health, reviewed 14 studies which in total involved more than 50,000 people.

The researchers urge more public health efforts to raise awareness of the issues for gamers, in the same way that has been done for live music and headphones. Of course, gamers could turn down the volume while playing to minimise the risk, but the study suggests that part of the problem is the length of time people spend being exposed to high volumes.

For example, the World Health Organization (WHO) says adults can safely be exposed to 80 decibels (dB) for 40 hours a week, which is about the noise level of a doorbell. Above that level, however, the safe amount of exposure to noise drops rapidly.

Adults should only listen to 90dB for four hours a week, and 95dB for one hour and 15 minutes a week, according to the WHO guidance. For children, the thresholds are even lower.

One of the studies evaluated by researchers found average headphone noise levels in four shooting games to be between 88.5 and 91.2dB. Another study found that impulse sounds - short loud bursts such as shooting noises - reached 119dB.

The paper also found that in three separate studies, boys were recorded as playing videos games more often than girls for longer stints and at higher volumes.

Some studies found correlations between gaming and hearing loss while other linked the activity with tinnitus. These used a combination of self-reported data and hearing tests to evaluate hearing. The authors acknowledge that more research should be done to establish a stronger link between gaming and hearing loss.

They add that the impact of e-sports, geographic region, sex and age should be looked into more closely. Some of the studies they looked at went back to the 1990s, when the gaming world was very different to now.

Only two papers published in the last 10 years objectively measured sound levels from video games or gaming centres, which are like video game arcades and popular in Asia. But the authors conclude that "the limited available evidence suggests that gaming may be a common source of unsafe listening".