Nightclubbers are being warned that exposure to loud music could do permanent damage to their hearing.
Noise levels reach 110 decibels on some club dancefloors
The Royal National Institute for Deaf People commissioned a survey of clubs in five cities, including Cardiff.
Noise levels in some clubs were found to be the same as an aircraft taking off.
The charity wants owners to provide clear information on noise levels for clubbers, and also to offer quieter areas in venues.
Other noise levels
City street 70dB
Underground railway 90dB
Pneumatic drill 100dB
Aircraft taking off 110dB
Noise levels were measured in three different areas of each club - the dance floor, the bar and the 'chill-out' area.
Sometimes the volume was so high, that even someone who only spends a few minutes a week on the dancefloor could be putting their hearing at risk, says the RNID.
Three nightclubs did not provide a 'chill-out' room - a designated quieter area. In the remaining 12, the noise was on average 16 times higher than the level recommended for the workplace.
In one 'chill-out' area the music was louder than it was on the dancefloor.
Regular rock concert-goer Glynn Pegler suffered a partial loss of hearing in one ear and suffers from tinitus.
He called the findings on noise a "wake-up call for the impact it has on you."
"I'd wake up in the morning and my ears would feel like they were full of water, I'd get a tingling sensation and then ringing in them.
"It gradually got worse. If I'm at a party or a gig, with background noise it's hard to have a conversation with someone, you have to ask them to repeat themselves."
"Now if I'm going to a gig I always make sure I have ear-plugs with me."
The RNID want club-owners to warn more of the dangers of noise
The RNID, which carried out the research in 15 nightclubs in Cardiff, London, Manchester, Edinburgh and Belfast, said it does not want to discourage people from clubbing or call for legislation to lower volume.
Instead, it wants club owners to act responsibly.
Cardiff club owner Giovanni Malacrino said he had speakers fitted with a noise limitation device.
"DJs like their music loud, it's their job. But if the noise reaches a certain level they have to negotiate. Imagine, if it's enough to damage the speakers, what it does to your hearing?
"We have areas to dance and areas to chill-out. You can get ear-plugs which look quite cool - maybe we can get some that are fluorescent yellow or something?"
The charity is producing posters for clubs as part of its Don't Stop The Music campaign.