Cars should make as little noise as possible. Adding noise is ridiculous. Every minority group for every activity in the universe want's their special needs catered to. So if this goes through everybody has to put up with 'noise' from there cars that they don't make naturally. No extra noise!
I could see a number of neat sound options:
Harley Davidson Motorcycle
Ride of the Valkyries
Star Wars Theme
Theme from Jaws (both fun and a great warning!)
In reverse - the standard Beep, Beep, Beep that we all know and hate (but it gets your attention).
If we are going down this road, then the new regulations need to apply to all vehicles, regardless of how it is powered (gas,EV,pedal power).
Personally I think it is just a knee jerk reaction to new technology. People need to be aware of their surroundings and take responsibility for themselves. If you are clueless enough to walk in front of a moving car because it is not loud enough, Darwin will see you to the exit door soon enough for a cause unrelated to EVs.
It is blind people who pushed for these minimum sound requirements. I am a blind engineer, and know that this problem has been under discussion for more than 10 years. In Montgomery County, Maryland, pedestrian safety campaigns recommend that pedestrians "make eye contact" with drivers. Good luck getting me to do that. Sound from an "idling" car is just as important as from one in motion. As much as possible, we need to be able to hear vehicles which may collide with us as we cross streets. I think manufacturers are going to be sensible about the sounds they select; a lot of groundwork has already been laid.
How do you deal with a bicycle coming by just as you step off the curb? Bicycles are even quieter than cars, even EVs. Should bicycles be required to make more noise as well?
Do you really trust that bicycle courier to see you as he's trying to make his deadline?
I live out in the country and often walk my dog along the side of the road (no sidewalks). I can usually hear a car coming, but I'm not hearing the sound of the engine. I hear the tire/road and the wind turbulence noises. Those aren't any different with an EV than for any other car with a decent muffler.
Perhaps we need some specific standards for this noise...otherwise everyone will play a different tune like in cellphone rings...specifying the dB levels in not sufficient...people need to know it is car coming!
I think that the most practical in terms of being easy to distinguish would be some sort of pulsing tone where the pulse rate increases in frequency as car speed increases. Also important, I think, would be a smooth transition to where the sound turns off. I also agree that some sort of standardization is needed with perhaps some options as to the tone frequencies chosen
First of all, it's not clear that lack of noise from EVs had any impact on the fatality stats posted in the article, is it?
But more to the point. Electric motors under load have their own wonderful growling-whining sound. My suggestions is, don't mess with it. If anything, just amplify the sound some, at low speeds, if pedestrian safety is a real concern. And it would be best to allow each manufacturer to tune the sound of their own products, same as they do with ICE exhaust systems.
Bert, you're absolutely correct. And re-reading the NHTSA reduction estimate quote, they see the reduction over the life of the various models... which ends up being a very small number on a year-by-year basis.
Seems to me the cheapest solution is to glue old playing cards to the tire rims so that they smack something as the wheel turns. A variation of this worked on my bike when I was a kid. ...although I would still run into people occasionally ;-)
The audio warning system should be integrated with one of the dashboard cameras that Yoshida reported on the other day, plus a Raspberry Pi (or similar) processor module. The processor takes the video feed(s) and detects and characterizes nearby pedestrians, cyclists, and animals (don't forget the animals!), then selects from a library of user-customizable audio tracks. Voila - the right sound for every situation. Of course, if the system is too user-customizable, it will be banned within six months once certain drivers figure out how to misuse it.
How about going back to that inverter whine that the very early transistor PWM controlled battery driven cars had? Sort of like the whine from some electric fork-lift vehicles? Of course those sounds may take some getting used to, but they could be quite simple to produce, just lower the chopper frequency.
Other than that, they could copy that well tuned exhaust note from the older "Grand Am" vehicles.
I agree with many posters here that tire noise is sufficient now -- and will be even more noticeable in an EV-dominant near future. We certainly should NOT be producing unnecessary noise pollution, just as we should minimize light pollution, etc. The blind can be given vehicle proximity sensors.
I think the sound should change in different areas. In sub-urban area, it could be easy-going music with low volume; in downtown, shopping malls, it could be high volume advertisement. The sound content should be able to be wireless transferred to vehicles from the neighborhood server.
We already have issues with hackers getting "into" cars and a few "car viruses" have been found. Imagine your car's sound generator (i.e. PA system) being rickrolled at 80 dB. But I'm waiting for someone to combine a virus with GPS data so it can play completely inappropriate sounds based on location. A mild example would be the U of M Hail to the Victors in the vicinity of the OSU campus. Racial or gang relates slurs could be more serious.
Someone already got the first half of my suggestion -- the clip-clop of horse hoofs. I would add, on cobblestone, with optional metal-banded wagon wheel adder.
Of course, for historical reasons, the horse-hoof sound recording would have to actually be of banging some coconuts together...
The syncopated clops of horse shoes hitting the ground. At 4 mph and below the gait would be a walk. At speeds from 5 mph to 10 mph the sound should transition to a trot. From 10 mph to 17 mph it should be a canter, and speeds from 18 mph to 30 mph the sound should be a gallop. In this way, sight-impaired people will know how fast a vehicle is approaching so they can adjust accordingly.
The problem is that we have such extensive noise pollution in our suburban or city environment that we cannot hear anything anymore. I assure that deep in the woods you CAN hear or rolling car with the engine OFF and that not even on a gravel but on regular road (you DON'T need to have an extra hearing). The solution should be to try to LOWER the overall acoustic NOISE floor so the SIGNAL would STAND OUT (can't recall when a higher S/N Ratio would be bad?).
There is this ridiculous safety argument about why the motorcycles need to be loud, taken to the full consequence everybody should remove any muffler from all the vehicles!
Drones are, in essence, flying autonomous vehicles. Pros and cons surrounding drones today might well foreshadow the debate over the development of self-driving cars. In the context of a strongly regulated aviation industry, "self-flying" drones pose a fresh challenge. How safe is it to fly drones in different environments? Should drones be required for visual line of sight – as are piloted airplanes? Join EE Times' Junko Yoshida as she moderates a panel of drone experts.