19-07-2019 | | By Paul Whytock
It's certainly true that slow-moving electric vehicles (EVs) are deadly quiet and there are cases where that operational silence has killed pedestrians.
Consequently, the European Union has made it a legal requirement that all new EVs coming into the EU after July this year will have to emit a noise when travelling at low speeds. Existing EVs and hybrids will have to be retrofitted. Precisely what sort of noise however is not clearly stated, although the EU is saying it must be relative to the vehicle.
Now, before getting into the more serious and technical aspects of this it did occur to me that what might be created here is a very lucrative retrofit automotive aftermarket for companies smart enough to offer soft and hardware retrofit noise-making gear to give your EV a simulated exhaust noise.
And despite the EU's request, it should be a noise relative to the vehicle its being used on we all know that the automotive aftermarket can sometimes be very creative when it comes to interpreting industry guidelines.
So for those of us who enjoy the occasional traffic light grand-prix scenario, the simulated noise choice when pulling away means we could dial-in an exhaust sound emulating the Ferrari GTB or perhaps you might prefer the Carrera 911s tone. The choices could conceivably include the roar of an F-16 fighter jet taking off, although the Brussels bureaucrats may not be keen on that.
For Tesla drivers, there is already a software-induced noise option available inside their cars which involves a rather lavatorial farting sound being randomly emitted from the in-car entertainment speakers. Tempting to say here that when the automotive big boys like Ford, GM, Mercedes get into the EV market we might find that Tesla cars have indeed gone with the wind.
Seriously though, this new EU legislation will force manufacturers of EVs to fit what has already achieved acronym status; an AVAS (Acoustic Vehicle Alert System). The AVAS noisemaker will have to operate at speeds from 1 to 12mph.
The thinking here is that EVs are very quiet, almost silent at those speeds and represent a real danger to pedestrians, particularly those with hearing and sight impairments and cyclists, especially those using earphones when cycling; something which I have to say is a pretty silly thing to do considering that hearing is one of the most important senses when it comes to road safety.
The speed range of 1 to 12mph has been arrived at because above those speeds its thought that EVs will create enough tyre, wind and mechanical noise to be noticeable.
I do have one question about all this though; what and where are the statistics that have created the need for EVs to make a noise? There are plenty of figures around that make all sorts of claims but hard facts are difficult to get hold of. Here's some realistic analysis.
The University of California conducted experiments where people wearing blindfolds said they could hear conventional internal combustion engine-powered cars approaching them as far off as 30 metres but when it came to a hybrid EVs that distance was reduced to just over thee metres.
Statistics further established by the NHTSA (the US National Highway Traffic Safety Administration dept) suggested that almost up to 45% of injuries happened when EVs and hybrids were moving at low speeds.
Now, what are the ambulance chasers in the US saying about all this? We all know that accident claim lawyers are very quick off the mark when they see a business opportunity and they reckon hybrids and EVs are nearly 40% more likely to cause pedestrian accidents.
These statistics coupled with the fact that sales of hybrids and EVs will undoubtedly continue to rise means the EU's requirement for noise-making vehicles at low speeds makes a lot of sense.
So how's this retrofit aftermarket going to happen? The answer is it already is and some smart ideas are coming through.
For example, miniature weather-sealed electronic audio speakers could be positioned in the vehicle's wheel wells that will emit the sounds and these will be projected in the direction the EV is travelling or turning.
Some retrofit companies are using actual engine recordings and these are transmitted through sound modules that will provide the realistic noises that emulate a combustion engine car sounds when it is idling, accelerating, decelerating or cruising. This means the system has to have sensor links to be able to adjust its sound types in accordance with the vehicle speed.
Some of the aftermarket systems will be attractive to the actual carmakers themselves, especially those that are programmed to emit a noise that not only relates to the EV speed but also its gear changes. Such programmable systems will also help the carmakers when they are going through prototype development of new EVs because experimenting with different sounds and settings can easily be adjusted.
So noisier EVs could save lives and for those tree-huggers that worry about noise pollution here's a case example where noise can help the environment. A very good pal of mine who lives in the countryside drives a lovely but noisy old Land Rover Defender through the country lanes. He likes the noise because it alerts wildlife and they stay clear of the road, particularly the deer in the area. So in urban conurbations instead of deer…think pedestrians!