Electric cars have a reputation of being silent vehicles and it’s expected. They don’t have internal combustion engines that typically make a lot of noise.
Instead of noisy engines, they have much more silent motors that allow people to cruise around silently.
However, that’s not all there is to how they work. In this article, we answer questions about EVs and noise.
Why Do Electric Cars Make Noise?
As we’ve established, they are usually silent on the roads. However, that’s not to say certain conditions wouldn’t cause them to become noisier.
Let’s begin with when they’re stationary. If you only start your car without actually driving it, it’ll be fairly silent. That’s because it’s not doing a lot of work.
Electric cars make more noise when you drive. At this point, the friction between the tires and the road causes a little noise. The noise increases with your driving speed.
Read more here about how Tesla tires are different, just like other electric cars have unique tires.
There’s also wind resistance to consider. Wind resistance is unavoidable in any moving vehicle, be it a plane, truck, or electric car.
So, although their motors don’t make a lot of noise, electric cars still make noise because of external factors. It’s noteworthy that noise due to tire and wind resistance may also be audible to the driver. We’d explain the effects in a short while.
Are Electric Cars Required To Make Noise?
All electric vehicles are required to make noise. We need them to make noise.
While their silent motors are great because it means less noise pollution on city roads, they pose a safety threat. Silent cars usually translate to unaware pedestrians and that increases the likelihood of car accidents.
Pedestrians are 19% more likely to get hit by an electric car than a car with a regular internal combustion engine.
Therefore, highway laws require that all vehicles emit sounds that are at least audible enough to alert pedestrians. These sounds are mostly needed at lower speeds since wind resistance would make cars more audible at higher velocities. Hence, the NHTSA doesn’t require cars to make such sounds at higher speeds.
As per the law, automakers resort to different techniques to make their cars audible. It’s not exactly ideal to alter EV motors to make them run much louder. Instead, most EV manufacturers make use of embedded audio systems.
Therefore, some electric vehicles still sound like they have engines. In the past, automakers used audio to convince customers of their car’s performance. Today, many of them use these sounds mainly for safety.
Why Do Electric Cars Make Noise in Reverse?
Most times, when drivers reverse, they do so at fairly slow speeds. You’d rarely see anyone speeding in reverse. So, except you’re reversing at 20 miles per hour, your modern EV would make engine noises to alert pedestrians.
Using audio seems like the perfect solution to curtail the safety deficiency that electric cars create. Let’s call it the “audio alert system”. So now you know that the audio system tech also applies when you’re reversing.
Modern vehicles have anti-collision systems that reduce the risk of hitting pedestrians or objects. They’re even more effective at slow speeds. However, this does not make audio alert system tech in EVs redundant.
Think of them as the basic layer of security all cars should have (the earliest vehicles were probably the loudest). Anti-collision systems are an extra layer of security and together they make roads much safer.
If you experience a loud noise while reversing, you might have a problem. In that case, get your EV checked. Drivers also complain that their EV reverse noise is extremely loud.
If that’s the scenario, invite a professional to examine it. There’s usually a simple solution for such issues.
What Does It Sound Like Inside Electric Cars?
Other than the audio alert system, most of the sound that an electric car makes while in motion is external. So, we can say the sound from the electric motor is negligible. Overall, electric cars have silent cabins.
While driving, you’d mainly hear the noise of wind slapping against the car surface at high speeds. The tire interaction with the road also causes a fairly audible noise.
Both the wind and tire noises are greatly reduced if your windows are closed.
Check also our article here about why electric cars are so quiet – in there you can hear what an electric car sounds like inside and outside.
Although EVs are mostly quiet, some sounds are pronounced under certain driving conditions. An example is the parking sound some EVs make when you put the gear selector in park. It’s usually a whirring sound that occurs because the brake pads grapple the disc pretty tight.
The battery management system also produces low noise when the battery temperature gets high. You’d be able to hear this sound from within when you’re charging your EV, especially DC fast charging.
That’s not all. When speeding up, like a non-electric car, you’d hear a noise that gives you feedback on performance. However, it wouldn’t be as loud as the noise from non-electric vehicles.
These are the sounds your EV would make under ideal conditions. Your electric motor would also emit a smooth, low sound. However, this might not always be a good thing since sounds help drivers easily recognize problems.
For example, in a gas-powered car, a popping noise from the engine might mean you should service the vehicle. On the other hand, an electric motor might have a problem and would still run silently.
Why Do Electric Cars Sound Like Spaceships?
If you’ve noticed any EV sounding spacey, keep in mind that it’s anything but accidental. Automakers have become creative with what they do with the audio alert system. Since they can now choose what sounds to use, they might as well use something cool.
For cars that sound like spaceships, it has nothing to do with the actual engine-in this case, motor performance. Instead, think of it as a ‘spaceship audio track’.
A good example is the Kia Niro.
I have happened to come across this quite a lot as one of our friends owns one of these. I would describe the sound coming from it as a “futuristic space sound” because it consists of 4-5 different smooth sounds played at the same time.
As time goes by, we expect more EVs to come with different sounds. What started as merely a simple safety precaution is now evolving into an opportunity to develop better aesthetics.
The idea is for manufacturers to come up with the best sound that matches the performance of the vehicle. That means the sound from any EV would mirror its exact performance all the time. In simpler terms, the audio would be adaptive and can even have actual vibratory effects.
For high-performance cars, it’s understandable why they’d take it pretty far. Before electric cars became a thing, muscle cars were known for their roar. With EVs in the mix, it’s only fair that automakers compensate with audio tech.
In the coming years, we also expect this to be a common practice among EV manufacturers.
Are Electric Cars Quieter on the Highway?
Relative to cars with ICEs (internal combustion engines), EVs are a lot quieter on highways or any type of road.
When you compare their noise on city roads to the noise they produce on highways, there’s also a significant difference. You’d expect them to be quieter on city roads than on highways and with good reason.
On city roads, cars move slower than they do on highways. Recall that EVs are so quiet that automakers need to add sounds to make people aware of their presence. Hence, ordinarily, we can say electric cars are noisier on highways (wind resistance and all).
However, it gets a little tricky than a yes or no answer.
Now, when EVs move at slow speeds, they get manufacturer-added sound. Also, when they move at higher speeds (typically above 20 mph) the wind resistance and tire friction create noise.
With these factors in mind, it’s difficult to assure you that EVs would always be noisier on highways. That’s because some manufacturers use sound systems that are loud and may overshadow wind resistance sometimes.
Can You Decide What Sound Your Electric Car Should Make?
Modern automobiles call for unconventional technology. However, electric cars that give drivers the option of choosing their preferred sound aren’t exactly commonly mass-produced at the moment. The good news for adventurers is; that’s all about to change.
The NHTSA permitted automakers to design cars with flexible driving sounds, as long as they meet the safety standards. That’s why it’s no surprise that soon, drivers would be able to choose what sounds they want.
So, if you’re an EV enthusiast and you’re excited about the news, you’re not alone. Surveys already show that it’s going to be a welcomed development.
Why Do Electric Cars Make a Humming Noise?
Most often, the humming noise is just standard procedure. Electric vehicles are very silent and humming has always been part of their mode of operation.
The coolant pump can produce a humming sound on a regular day. So, humming isn’t usually a cause for concern.
However, you’d hardly hear the humming noise because it’s usually drowned out by the car’s “fake engine” sound. At higher speeds, the humming could get overshadowed by the sound of wind slapping across the windshield.
However, not all humming sounds are good. Some humming sounds signify a problem, and that’s where it gets tricky. This is because it’s hard to tell the difference between a regular hum and a bad one.
When you have a bad wheel bearing, you might hear a humming sound when you drive. It gets louder as you speed up, so that’s a good way to tell that there’s a problem. Recall that regular hums get overshadowed by other noises.
Also, if your wheel bearing is faulty, the humming might be accompanied by other symptoms. So, try to keep your ears sharp for any accompanying squealing or growling noise. If you believe you have a faulty wheel bearing, stop driving if it’s an option and call your mechanic.
Please keep in mind that there are many electric cars from different manufacturers.
That means there’s no universal answer that applies to all EVs under the sun. However, our answers here can apply to a high percentage of electric vehicles.
If they don’t apply to yours, try to get information peculiar to your car brand or model.