Roofless driving could send you deaf

5/1/11

Experts have warned motorists that driving in a convertible car with the roof off could send you deaf due to the levels of noise generated by the wind rushing over the car at high speeds.

At speeds of 75mph, noise levels were recorded at 100 decibels – the equivalent of a jet plane passing overhead or a nightclub. Even at 55mph they reached levels at and above the recommended level for the workplace of 85 decibels – as loud as a construction site or a diesel train passing by.

The levels of noise were also said to experience 'spikes' in volume, such as when the car was passing a large lorry or a motorbike.

Researchers carried out experiments in five different cars, including a Nissan 350Z, a Porsche 911 and a Saab Aero, and took recordings at 55mph and 75mph. They kept a controlled in-car environment with the radio and air conditioning switched off, while the passengers didn't talk to one another and didn't operate the horn.

They also took readings with the roof closed, but this produced no abnormal recordings, suggesting there was minimal risk of ear damage driving on the motorway with the roof up.

Dr Anthony Mikulec from the Saint Louis University School of Medicine, Missouri, who oversaw the study, said: "When the convertible automobiles were driven with the top open, high levels of noise were consistently recorded.

"Although driving for short distances under such levels of noise exposure is unlikely to cause a significant degree of noise-induced hearing loss, our study demonstrates that long duration driving at high speeds with the convertible top open will increase the driver's risk of hearing damage.

"In light of the results of this study, we are recommending that drivers be advised to drive with the top closed when travelling for extended periods of time at speeds exceeding 85.3kph (52mph)."

The study was published in the Journal of Laryngology and Otology.