ISLAMABAD, December 10 (Online): Your hearing may be at risk if you were born to be wild.

In an informal survey of 33 motorcycles, University of Florida audiologists found that nearly half of them produced sounds above 100 decibels when throttled up -- equivalent in intensity to a loud rock concert or a chainsaw.

The survey is part of an ongoing effort to identify recreational activities that may pose a risk to hearing, including noise levels experienced by motorcyclists, the researchers said.

The audiologists noted that the sample was small and not representative of all makes and models and those motorcycles with exhaust systems modified to make them louder. So formal research is needed to measure noise levels under typical riding conditions and to determine whether these early survey findings can be generalized to a larger number of bikes, they added.

Exposure to noise at 100 decibels is safe for only 15 minutes and permanent hearing loss can occur with prolonged exposure to noise levels of 85 decibels or higher, says the National Institute for Occupational Safety and Health.

"Almost all of the motorcycles we tested reached action-level noise, which in the workplace would require ear protection," UF researcher Joy Colle said in a prepared statement.

"The loudest bike we tested measured 119 decibels with the engine revved, and the recommended exposure time at the level is only 11 seconds."

"Potentially, the vast majority of motorcyclists could be exposed to dangerous levels of noise," Colle said.

Motorcycle helmets don`t offer any significant protection against noise. But inexpensive foam earplugs can reduce sound levels by 20 to 25 decibels, Colle said.

A ringing sound in the ears immediately after exposure and muffled hearing are warning signs of noise-induced hearing loss, which is permanent.