Tested; Seven different types of convertible cars driving at 50, 60 and 70 mph with windows raised and down. They placed a noise sensor on the traffic side of the car and took 3 separate measurements in each condition. All tests were done on similar roadways and in non-rush hour traffic to minimize data contamination.
There was no difference in noise levels between the different types of car or at the speeds measured. All of the averaged (mean) testing results with the windows down exceeded the OSHA criterion limit of 85 dB (89.1 dB +/- 0.7 dB). Just rolling up the windows of the cars,still with the top down, dropped all noise levels below accepted levels to avoid hearing loss (84.2 +/- 1.0 dB). These results did not take into account the impact of rear wind deflectors since not all of the cars had them available. Noise levels were increased when the test cars were passed by loud vehicles (i.e. big trucks).
Considar keeping your windows up and you may want to wear hearing protection while you are driving. Hearing protection is typically not a good idea when you drive since it can limit your ability to hear traffic and other environmental sounds around you. In short, ear plugs can be dangerous and I do not recommend that option.
You can tolerate 85 dB for up to 8 hours so take breaks if you need to do the entire long drive with the top down. If you turn up your radio to hear the music with the lid off of your car, be aware that you may be increasing your noise exposure as well.
Source http://www.swedish.org/blog/2011/04/hearing-loss-from-driving-a-convertible-reality-or-myth
There was no difference in noise levels between the different types of car or at the speeds measured. All of the averaged (mean) testing results with the windows down exceeded the OSHA criterion limit of 85 dB (89.1 dB +/- 0.7 dB). Just rolling up the windows of the cars,still with the top down, dropped all noise levels below accepted levels to avoid hearing loss (84.2 +/- 1.0 dB). These results did not take into account the impact of rear wind deflectors since not all of the cars had them available. Noise levels were increased when the test cars were passed by loud vehicles (i.e. big trucks).
Considar keeping your windows up and you may want to wear hearing protection while you are driving. Hearing protection is typically not a good idea when you drive since it can limit your ability to hear traffic and other environmental sounds around you. In short, ear plugs can be dangerous and I do not recommend that option.
You can tolerate 85 dB for up to 8 hours so take breaks if you need to do the entire long drive with the top down. If you turn up your radio to hear the music with the lid off of your car, be aware that you may be increasing your noise exposure as well.
Source http://www.swedish.org/blog/2011/04/hearing-loss-from-driving-a-convertible-reality-or-myth