Adaptive tech helps keep electric cars' warning sounds from disturbing the peace

Adaptive tech helps keep elect...
Tests of the system were performed at a quiet location in Tiller, near the Norwegian city of Trondheim
Tests of the system were performed at a quiet location in Tiller, near the Norwegian city of Trondheim
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Tests of the system were performed at a quiet location in Tiller, near the Norwegian city of Trondheim
Tests of the system were performed at a quiet location in Tiller, near the Norwegian city of Trondheim

Although many people like the fact that electric cars don't produce any engine noise, this means that blind pedestrians can't always hear the things coming. Having the cars emit a warning sound when traveling at slow speeds is one solution, and a new system could help keep that sound from being any louder than necessary.

In a number of countries, electric vehicles are already required to be equipped with slow-speed warning sound systems, or they soon will be. The problem is, if that sound is loud enough to be heard in busy downtown traffic, it will be unpleasantly loud in quieter environments such as residential neighborhoods.

With that in mind, a team from Norway's SINTEF research group is developing what's known as an "adaptive sound" system. The technology monitors the ambient noise levels of the environment utilizing a car-integrated microphone, and then responds by raising or lowering the volume of the warning sound accordingly.

In order to determine just how loud that sound needs to be, the researchers drove an electric car equipped with the system down a quiet stretch of road, which blind volunteers sat along side of. Loudspeakers produced traffic noise at various levels, which the adaptive sound system responded to. As soon as the volunteers were able to hear the car's warning sound, they pressed a button to indicate that it was loud enough.

"A number of car manufacturers, including Nissan, General Motors and Renault, have shown interest in the results of this project," says lead scientist Truls Berge. "Norway has the highest density of electric vehicles in the world, so it's natural that electric car manufacturers look to us with regard to traffic safety and research in this field."

Source: Gemini

Familiar with "The Ambulance Down In The Valley"? (See, for example, This story can mean different things to different people, but one of its messages is to not focus on the wrong thing. Why are we forcing every EV to have a noisemaker to disturb everyone around rather than offering a solution to the small population that this affects? Wouldn't a service animal warn them of oncoming traffic? What about a personal radar device that beeps only in their ear to communicate a car is approaching?
If we are really concerned about everyone else taking responsibility for protecting the visually impaired, why only force EVs to have noisemakers? Bikes are quiet too and can do much damage if they run into someone. What about luxury cars that are super quiet? Why aren't they being forced to make noise? If this were really about a vehicle not making enough of a warning noise, then these laws wouldn't just focus on EVs.
While it makes sense that this is being studied in Norway, the country with the highest percentage of EVs to date, I think it's a not really a problem because tire noise is on par with or higher than engine noise up to a city speeds.
Maybe they should do this with on many ICE cars that are whisper quiet these days, the only sound you hear many of them is the tyres on the road, just like an EV. More than once I have had to jump out of the way of virtually silent cars ...
@ImCurious, you have a few good points. What surprises me is that no one, in all these quiet EV studies has pointed out is that the ultimate responsibility for operating a motor vehicle safely belongs with the operator! Why give the vehicle an automated noise maker to let the sight-impaired hear it coming? Because the operators of today's vehicles do not properly operate them safely! Pedestrian crossing stings net hundreds of crosswalk driver violations and no noise maker will change that. Tires on the road make quite a bit of noise, even for a "silent" EV.
Unfortunately, I've found too many technological "improvements" simply reduce driver responsibility and that's not the correct direction to be heading. Let's stop with the ambulances and build the correct fences.
Blind people are the LEAST in need of help hearing an electric vehicle. They are attuned to any sound, and they can easily hear the tires and or the gearing of the motor/transaxle, especially in the country.
Anyway, almost all people getting hit by cars today are hit due to total inattention to their surroundings, with their heads in the phone or tablet.