With so much attention given to environmental concerns you’d think that an electric car is the perfect sin-free solution, but you may be wrong. Being as quiet as a mouse, these nifty travellers can catch you quite unaware


Electric and hybrid cars are very much on the rise in terms of the number of them we now see on the roads. There are thousands of charging points around the country (and the world as a whole), and electric models such as the Toyota Prius are breaking into top ten car lists compiled by industry professionals.

There is little doubt that electric cars are great for the environment but they are, apparently, not without their faults. While they cut down on carbon emissions and other types of harmful environmental pollution, they’re also doing their bit for noise pollution in the sense that they’re so quiet that there are times when pedestrians can’t hear them coming.

The issue goes back to at least 2008, when electric and hybrid cars were first becoming widely available. Hybrid engines are intrinsically quieter than purely fuel-powered engines, and this can be a major problem, especially when you consider the abilities of blind pedestrians (which are mainly limited to their sense of hearing) to recognise an approaching vehicle. At that time, a study was undertaken at the University of California in which blindfolded participants were required to say when they could hear a (simulated) car approaching at five miles an hour. A Honda Accord was identified within 36 feet, but a Toyota Prius could not be heard until it was 11 feet away, giving the person (hypothetically) less than two seconds to react to it.

There have been calls in the wake of this research for car manufacturers to add an artificial sound to their hybrid models. The US Congress passed a Bill confirming these plans, but delays have meant that they haven’t yet come to fruition — the National Highway Traffic Safety Administration recently stated that the November deadline for finalising the regulations will now not be met. It now looks as though it will be March 2016 at least before any decisions are made.

What sort of sound should it be?

One of the issues is the fact that nobody can decide what the sound should be. Because of the way the human brain works, our ears identify the sounds that are coming closer and take special notice of them as opposed to sounds that are static or moving further away. This means that any sound added to a hybrid car doesn’t have to be loud or irritating — in fact, louder sounds such as beeps and chirps are more likely to be distracting than warning. The sound may take the form of an artificially added car engine noise so that pedestrians can identify it more quickly.

While certain models have been brought onto the market with a warning system included, the last of these was in 2013, so it is important for manufacturers and safety administrators to work together to reach a solution that satisfies all involved as quickly as possible.