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Global Automakers urges NHTSA to set a safe, but not too loud minimum sound requirement for hybrid and electric vehicles

In its comments to the National Highway Traffic Safety Administration’s (NHTSA) proposed rule to add sound to hybrid and electric vehicles, the Association of Global Automakers is asking the agency to find a noise level that effectively alerts pedestrians without being excessively loud.

Striking a balance is important. While we support the intent of the regulation to assist pedestrians, we have concerns that the current proposal may lead to alert sounds that are excessively and unnecessarily noisy to others inside and outside of the vehicle.

—Michael Cammisa, director of safety for Global Automakers

In 2010, Global Automakers worked with lawmakers, the National Federation of the Blind, the American Council of the Blind, and other auto industry groups on the Pedestrian Safety Enhancement Act which directed NHTSA to undertake this rulemaking. The rulemaking is intended to assist pedestrians in identifying the presence of hybrid and electric vehicles by requiring automakers to add sound to these quiet cars.



This is going to take higher frequencies (which are more easily blocked and die out more quickly with distance) aimed in the direction of motion.

In other words, the exact opposite of loud pipes on motorcycles.


Maybe it should sound like a car.


The saund level minimum shall be established only for the motion directio i.e. 10 m of the car front slightly to the right and max. in othe direction at low speed. At high speed there is enough sound.


Here is the NHTSA page with the WAV files of the sounds they are considering:

Personally, I think it should sound like an electric car, or maybe an elephant.


NPR suggested that it should sound like the flying car from The Jetsons.

I'm sure people will re-program cars to sound like whatever they want.  Star Wars afficionados will make theirs sound like Tie fighters.


The folks at Audi spent a lot of time developing a cool sound for their R8 E-Tron electric sports car. There are several youtube videos showing development in the sound lab, but this one shows off the car's synthetic sound outside in a real-world situation.


I vote for EPs solution but with an on/off triggered by pedestrian detection. Noise should not be generated unless absolutely required.


Failure of car to detect a pedestrian would make it much more likely that the pedestrian would fail to detect the car.  That's a really dangerous failure mode.

Electronic warning sounds can be selected to be less obtrusive.  So long as they're no worse than the tire and wind noise of a vehicle moving at the local speed limit, it's hard to argue that it ought to be turned off.


My problem is with EVs being singled out. Top end luxury cars are extremely quiet and I've had plenty of times where people walk out in front of my Mercedes in parking lots or in slow moving traffic without knowing I'm there.
There should be a minimum noise for ANY car going at slow speeds, not just EVs or FCVs


THis whole effort is stupid. Once agaisn the vast majority is to suffer for the needs of the few, when it is totally un-neccessary.

There is a certain portion of the population that is visually impaired. We also have technology for low power short range radio, that is little used.

A smart way to address the problem is to have "too quiet" vehicles radiate such a radio signal, warning of their approach. Only the visually impaired need to monitor these broadcass while the vast majority of the population could revel in the blessed sounds of... silence.

Will S

Unnecessary. As DaveD points out, many luxury cars are very quiet as well - will those also have noise added to them?

Cyclists don't make noise, and pedestrians have to keep them in mind as well, so this doesn't make sense.


Cyclists are often required to have a bell or horn to warn pedestrians precisely because they are otherwise too quiet to detect by ear.


In principle, no noise (pollution) should be generated unless strictly required to save lives and injuries and/or reduce accidents.

Pedestrians, bicycles and other vehicles reliable detection is no longer a challenge nor very costly to do. It will certainly be incorporated in future cars as other driver's assistance.

It should simply be mandate for all future electrified vehicles.

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