Adding sound to electric vehicles

harrisonpatm

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From the video description:

For over a century, the internal combustion engine powered vehicles with an intricate combination of moving parts and tiny explosions. That combustion process inevitably made noise, and that noise came to define the background soundscape of our roads, cities, and day-to-day life. But as hybrids and EVs became increasingly mainstream — and more of their near-silent electric motors filled the streets — it became clear that silent vehicles didn’t fit in the ecosystem we’d built around cars. Spearheaded by associations of the blind and visually impaired, legislation eventually began to require electric vehicles to emit an artificial engine noise out of hidden external speakers. These hidden speaker systems, called “Acoustic Vehicle Alerting Systems” — or AVAS — had to meet certain sonic criteria. But they were also a blank slate for sound designers to decide how the cars of the future should sound.

Seems kind of silly to me. There are just so many problems with a dependent and car-centric world, I feel like effort should be being made to make to make streets safer for people in general. Cars need need to avoid people, not the other way around.

In any case, I thought it was interesting enough to share. I've seen on the forum multiple times, users joking that someone's DIY electric motorcycle conversion needs external speakers to mimic a motorcycle engine, because "lOuD pIpEs SaVe LiVeS, duh!" Didn't realize that there was already some legislation in place.
 
I was thinking one could affix bottle caps to the tires. Then you’d hear the sound of a tap dancer.

#BottleCapsSavesChaps

But yes, better cycling infrastructure would be better. I bike on some narrow bike lanes and there has been construction for many years. They are not widening bike lanes. They are putting updated crosswalks. I have to jut in to traffic pretty often to avoid the “lane closed” signs.
 
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Squarewave controllers do a great job of adding sound!
 
Squarewave controllers do a great job of adding sound!
My moped conversion has a 1:7 chain drive, that isn't perfectly straight, and the cheapest Aliexpress controller that I could find in the power range I needed. It makes plenty of sound!
 
Why would you want to be heard? If I'm rolling through East St. Louis, IL at 2 AM, I don't want anyone to hear me. If I want them to hear me, I play some Satanic Black Metal through the sound system. Which doesn't happen much, so otherwise, silence is preferred, mostly because it is a lot easier to hear everything going on around me.

Hubmotors are nice because they offer silent operation when coupled with FOC controllers. I'll pass by multiple dangerous places without anyone hearing me roll by. Below about 20 mph, there's not enough wind/tire noise for the trike to be noticed in an otherwise silent area from 100+ feet away. For the mountainbike, this threshold of being imperceptibly quiet is closer to 15 mph. In either case, motor silence has its uses.

And I DON'T want to be seen at night unless I have my lights on. Then I do, but there's no guarantees when Boobus Americanus Ghettopotamus is looking at their ironically-named smart device instead of what is within their vehicle's path, in which case noise also increases your chances of being noticed.
 
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My moped conversion has a 1:7 chain drive, that isn't perfectly straight, and the cheapest Aliexpress controller that I could find in the power range I needed. It makes plenty of sound!

Fits the character of the build pretty well!
 
If anybody is curious, I found the October 2009 report (updated in 2011) from the NHTSA, which offers the majority of the reasoning behind the AVAS legislation. At least in the US


Curious that the sample size for electric vehicles was (and still is) so small. Seems like another example of small data sets being used for sweeping generalizations.
 
I didn't watch the video
Since the report was last update in 2011 I would Guess that it has turned out not to be as big of a problem as people thought
later floyd
 
I didn't watch the video
Since the report was last update in 2011 I would Guess that it has turned out not to be as big of a problem as people thought
later floyd
Proponents of the regulations would say that adding the noise worked... who's to say?
 
I am in California which has more ev's/hybrids than most places in the US, the only sound I hear from the ev's/hybrids at low speed is an electrical hum. If that is the alerting noise I am ok with it. I walk in the surrounding neighborhoods for 2 to 4 hours a day. Or maybe I have become so used to the noise it has dissappeared?
later floyd
 
If that is the alerting noise I am ok with it.
I know you said that you didn't watch the clip, but in the clip it discusses how each manufacturer gets to pick what the sound is, and often times they will simply simulate an electric motor turned up to emulate the speed the vehicle is traveling. So yeah, often times when you hear the electrical hum at low speed, it's simulated.
 
Squarewave controllers do a great job of adding sound!
Also sub-10 kHz pulse width modulation does a good job of that.

So much bending over backwards to avoid the real issue! Cars don't belong among humans in city streets any more than airplanes or helicopters do.
 
I think it was Fat Freddy in 'The Fabulous Furry Freak Brothers' by Gilbert Shelton, who planned to aurally augment his Beetle (?) with the sound recording of a fully loaded semi pig transport doing an emergency brake.
 
So much bending over backwards to avoid the real issue!
That's why I thought it'd be a worthy post. So much work and effort to make sound when it isn't necessary, just to "fit int" with a car society
 
I'm moving stuff around right now, and I'm using a modern pickup truck for the first time. The rest of my life is characterized by having to tolerate horrible deafening noises from all kinds of motor vehicles, so it's weird to be in a crappy noisemaking contraption and have it be almost completely silent (and numb, and mostly blind) inside.

I think it's only right that any car or truck should have to be louder inside than it is outside, and that its exhaust should have to pass over the driver before going on to pester anybody else.
 
I never really understood this "argument" of electric cars being dangerous because they were "too silent"
We're not in 1980 anymore, now gas engine are pretty much inaudible under normal driving condition. 90%+ of the noise cars make at stabilized speeds is due to tire friction and aerodynamic drag.
Electric cars also have tires and also have aerodynamic drag, so they're pretty much the same. The only clear difference you might hear is under acceleration. But acceleration is a relatively small percentage of overall driving time if you think about it.

Here in Shanghai there are loads of electic cars in the streets, arguably more than anywhere else in the world. Small and average sized delivery trucks are now almost all electric. We even start to see conventional big trucks converted to electric propulsion in the streets since a few months. People are able to hear all of these vehicles and you don't see more accidents than with gas engine cars. The only real danger of electric cars in my opinion is accidentally hitting the accelerator pedal. With the instant torque and loads of available power we see a lot of serious accidents from some careless/unexperimented drivers.

I agree with Chalo that the noise we need is inside the cabin, not outside.
I always wanted to build myself some kind of fun device that would imitate an engine sound. Imagine being able to download any engine sound of your choice, then program your own custom simulated gear ratios, torque maps, shift delays, etc. You could change gears with paddle shifters , you'd get the kick in the ass during gear shifts, the thrill of the sound of a racing V12, the vibrations....

You could change anytime you want, get to choose between driving a Lexus LFA V10, a Lambo Murcielago V12, a Maserati GransportV8, a BMW inline six or even a early 2000s Formula one V10 sound if you wanted ... You could set the corresponding torque and power figures so the electric motors would behave the same as the real engine, basically you could have a hundred cars instead of just one.

Sure that would be simulated, but it would still be super cool and you could disable this mode just by pressing a button if having fun in your life isn't really your thing,
Unfortunately I couldn't DIY such a thing because it seems like modulating an engine sound isn't a simple task at all and I am unfortunately not clever enough to figure out how to do it myself (at least it's not simple if you want the sound to be good and realistic, it was possible to make a crude and crappy system relatively simply)

I'm sure it would be a viable product, because not having engine sound is usually the number one complain of car enthusiasts against EVs. In my opinion this could be the holy grail, because it solves most of the complaints people have agains EVs being boring, it would even create entirely new markets for downloadable car sounds, motor/transmission setups, chassis and traction control tuning, etc.
 
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Step 1: trap controller

Step 2: design stator to be frickin' loud:
 
I always wanted to build myself some kind of fun device that would imitate an engine sound. Imagine being able to download any engine sound of your choice, then program your own custom simulated gear ratios, torque maps, shift delays, etc. You could change gears with paddle shifters , you'd get the kick in the ass during gear shifts, the thrill of the sound of a racing V12, the vibrations....

.... it would even create entirely new markets for downloadable car sounds, motor/transmission setups, chassis and traction control tuning, etc.
Ring tones for cars! That could be a money maker, if only people would buy ev's.
 
This is a very nice ...er... proximity warning device, that also provides a bit of electricity and heat in colder climes. :devilish:
It is in fact so 'nice' that a fake gearbox (variable load generator of some sort, talking to the controller) would round it off very nicely.
 
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