If you’re particularly sensitive to noise, your daily commute can be pretty frustrating. After all, if your car isn’t soundproof, you’ll have to put up with all sorts of external sounds in addition to the ones coming from your own vehicle. But don’t worry; there may still be hope for the future. Many new car models nowadays are being equipped with active noise cancelation features.
In this article, we’ll talk about how this technology has changed the way we deal with road and engine noise. However, we’ll also talk about some more immediate ways to create a more soothing environment inside of your car.
But first, let’s talk about what active noise cancelation is and how it came to be.
What Is Active Noise Cancelation?
Even though the first active noise control system was patented way back in 1936, it didn’t come into use until the 50s. Around that time, the system was used to reduce noise levels in helicopters and airplanes. Clearly, we couldn’t have pilots losing their hearing. So engineers needed to find a solution quickly.
But how do noise control systems normally work? Well, there are several key components you need for a noise control system based on the process of destructive interference.
First, you need a microphone that picks up the frequencies of surrounding sounds. Then, a machine has to invert the polarity of those waves. Lastly, you need speakers to play the opposite beats back to the user. Ideally, this whole process should happen within a very short time span, in order to cancel noise instantly.
Now, as I have mentioned, this technology was first used in aircraft cockpits. However, soon after, the system was incorporated into other products.
Most significantly, the Bose Corporation created noise-canceling headsets that were used in the Rutan Model 76 Voyager around-the-world flight in ‘86. That quickly lead to the development of other noise-canceling headphones, which have since entered the consumer market.
Now, you may be wondering: why would the average consumer even need products with noise control technology? It’s one thing to say pilots need noise-canceling headphones — they have to deal with engine noises measuring over 105 decibels inside the cabin. But are the active noise-canceling products that make it to the market similarly effective? Let’s find out.
Are Commercial Active Noise-Canceling Products Effective?
Overall, I’d say that most of the active noise-canceling headphones you can find online are pretty effective. More to the point, there are plenty of fantastic benefits to choosing one of those products instead of just relying on cushioning to seal your ears or earbuds to plug out the noise. Firstly, noise-canceling headphones can actually save your hearing.
In a previous article, I explained that noise-canceling headphones are safer than regular ones. Usually, when people use regular headphones, they tend to turn the volume all the way up to block outside noise. However, since active noise control technology already blocks out surrounding noise, users tend to leave the volume levels within a safe range. So, basically, using noise-canceling headphones protects your hearing.
Simply put, headphones with active noise control technology provide a superior listening experience. After all, these kinds of headphones take most of the ambient noise out of the equation. However, this system isn’t magical — so you will have to put up with some sounds.
Namely, there is a pretty significant catch here, which is that the technology isn’t truly instantaneous. Because of the time it takes for the system to invert the external frequencies and play them back, active noise control can only cancel out repetitive sounds. What’s more, noise-canceling headphones usually only cancel out low frequencies. So what does that mean when we’re talking about using this system for cars?
Active Noise Cancelation for Cars
As you’ll recall, active noise control technology was used to essentially soundproof airplane cabins in the 50s. So it’s not that much of a stretch to say that it could do something similar to the cabin of your vehicle. In fact, that’s exactly what happened in 1992, when Nissan launched a car with an active noise control system.
And so, the Japanese Nissan Bluebird became the first, but certainly not the last of this type of car. Since the 90s, we have seen luxury cars jump on this trend. However, manufacturers didn’t start making cars with active noise cancelation technology widely available until about 10 years ago.
Now, how does that one fault of active noise control technology impact its usage in the automotive industry? Well, as it turns out, that defect works out pretty well when you’re in the driver’s seat.
After all, when you’re driving, you don’t want to risk not being able to hear important sounds. You’d hope that you’d only miss hearing that one guy honk at you for no reason. However, you also wouldn’t be able to hear a fire truck or an ambulance vehicle.
So, at least, there’s no chance of missing audible traffic cues if the noise control system in your car only cancels out low, continuous sounds. Of course, when it comes to active noise control in cars, the real problem isn’t identifying which noises to cancel. So what’s the true reason why only luxury cars have had these systems up until about a decade ago?
Essentially, it comes down to the cost of the various parts necessary to make the systems work. Ultimately, they were much too complicated to produce cheaply. So how did car manufacturers figure it out?
What Does Active Noise Cancelation for Cars Look Like?
Obviously, active noise control systems for cars are very different than those they put in headphones. Typically, the headphone components are all close to each other, with the microphone, the inverter, and speakers all stacked together. Naturally, the system has to look a bit differently in cars. That’s why engineers are still devising different noise control solutions.
In fact, many car manufacturers have partnered up with audio equipment companies in recent years. The most important consideration was to make the parts simpler and lighter. Soon enough, active noise control technology was adjusted and adapted to passenger vehicles. However, a brief search online will show you that they’re all using fairly similar mechanisms.
As you’ll see in this video from HARMAN, their HALOsonic active noise management depends on several parts:
- Accelerometers near every tire, which measure tire rotation
- An adaptive controller
- Four microphones inside the cabin for feedback adaption
- Speakers, to close the loop
That sounds pretty familiar to the system I’ve already explained, right? Well, the Bose Corporation also came out with an audio management system for cars. According to the company, their system has nearly identical components, as showcased in this video.
The accelerometers above each tire measure the vibrations, then the system flips the frequencies. Finally, the internal microphones pick up data for the final adjustment before the result comes through the speaker system. In theory, all of these systems should be equally effective, allowing you to make hands-free calls or listen to music.
Cars With Active Noise Cancelation
Nowadays, plenty of cars use active noise control to create a quiet cabin. Most luxury sedans have it: the Lincoln Continental, the Lexus LS, and the Cadillac XTS, to name a few.
Indeed, some companies go above and beyond to achieve the perfect driving atmosphere. The Nissan Maxima keeps the company in question at the forefront of innovative active noise control. In fact, the vehicle even has an Active Sound Enhancement system, which actually makes the engine sound better in the cabin.
The Honda Accord uses similar technology which both cancels out some noises and enhances others.
Now, personally, I like being able to hear what my engine actually sounds like. I wouldn’t want to miss a suspicious noise. However, I can understand the sentiment behind the feature and wanting a generally quieter driving experience.
How to Improve the Soundproofing of Your Car
Even the best active noise cancelation system won’t work unless the car already has decent passive noise insulation features. That means that the vehicle already has effective seals that won’t let noise through. However, if that’s something your car is lacking, there are ways to fix that.
If you’re looking to lessen the amount of road noise you can hear in the cabin of your car, I suggest focusing on the doors, roof, and floor. Generally, the doors tend to be the most vulnerable to letting in sound, though — just like they are in our homes. So you might want to open them up and stick some sound deadening mats to the sheet metal.
While you’re at it, check the weatherstripping rubber along the inside of the doors. If your car is particularly old or battered, the weatherstripping may be letting in air. Even if you put aside the soundproofing implications, that also means that your AC won’t be as effective.
If you want, you can stop there. However, you can also implement more comprehensive soundproofing methods if you so choose.
Having to listen to incessant traffic noises can be frustrating and draining — it can even impact your driving. However, you probably shouldn’t completely soundproof your vehicle either. After all, not being able to hear your surroundings while you’re driving could be a disadvantage.
Fortunately, active noise control technology is the perfect solution if you’re looking to only quiet specific sounds. Namely, it can only stifle continuous, low frequencies such as road vibrations, air noise, and engine sounds. Still, even that would allow you to give your ears a rest and stay sharp while you’re driving.
What’s more, having a quiet environment in the cabin would also let you enjoy music, audiobooks, or podcasts. You could just sit back, put on your tunes, and focus on driving. Who knows — your daily commute might even become a relaxing experience for you.
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