There is EU legislation limiting the maximum output of headphones to 100dB, which is akin to an ambulance siren.
There is also a setting on iPhones to “reduce loud audio” which allows the user to manually lower the maximum output down to as low as 80dB, which is equivalent to background chatter in a restaurant.
Android also restricts the voltage output of the earphone socket in a bid to cap the volume emitted by headphones to 100dB.
However, this only applies to headphones supplied with phones and many in-ear and over-ear devices made by other brands do not limit the noise level.
Low-volume headphones with a maximum output of 85dB are available and aimed at under-18s as the smaller ear canals of children means that loud noises are even louder to younger people.
Dr Couth said that there are some headphones on the market which can exceed 120dBs, which is roughly the same level as a chainsaw or a jet plane taking off.
“However, it’s not just the level of exposure that is important, but also the length of exposure,” he said.
“For an environment that is 85dB, the maximum safe exposure time is eight hours. For every 3dB increase, exposure time is halved, so four hours for 88dB, two hours for 91dB, and so on. So at 120dBA, the maximum safe exposure time is about 30 seconds.”