Traffic Noise Pollution

Vehicular traffic noise pollution may be one of those everyday pollutions that we overlook, considering it to be annoying but not really detrimental to our health or well-being. In reality, traffic noise might just be killing many of us slowly, as well as causing lots of other irritations that we just can’t get away from.
Healthy human hearing is very sensitive, so to be subjected to prolonged exposure to traffic noise estimated to be in the range 50 to 95 dB (of equivalent sound level, or the energy mean sound level, to use the right jargon) can be both annoying and damaging to your hearing. The last century is the noisiest in the history of the world due to the advent of fossil fuels.
It seems every country has their own limits for what levels are considered to be non-damaging to the human ear, some say 85dB for more than 8 hours a day (which means 88dB for 4 hours, 91dB for 2 hours and 94dB for 1 hour, in terms of acoustical energy exposure). For sleeping, the World Health Organization proposes limits of 30 dB(A) constant noise and 45 dB(A) for individual noise events.
More than just hearing damage though, there is the stress of noise pollution that can lead to sleepless nights, anxiety, higher blood pressure and even increased chances of heart failure. Missing out on sleep makes people irritable and compromises the immune system, that lack of sleep might also mean a lack of concentration at school or work, which mean lower grades, lower pay rises and maybe an increase in accidents. Sleepless nights can also make partners grumpy the next day, meaning less blissful partnerships and maybe even contributing to break-ups.
I think we should all be looking forward to the arrival of electric and/or solar powered vehicles, they will be a lot quieter than today’s gasoline and diesel powered ones, so quiet in fact that governments might have to legislate that manufactures make them more noisy. The concern is that children and visually impaired people might not hear the vehicles coming when they are crossing the road or in parking lots.
Lotus, the specialist UK car manufacturer, has demonstrated a 300W externally mounted sound system on a Toyota Prius Hybrid which made engine like sounds when the vehicle was in hybrid mode but which switched-off when the internal gasoline engine came on. Hopefully the regulations won’t turn your future electric vehicle from a whispering buzz into a roaring V8, otherwise we won’t be able to look forward to quieter, more harmonious and healthier cities.