Passive Noise Isolation vs. Active Noise Cancellation

Passive Noise Isolation vs. Active Noise Cancellation
What’s the difference between passive noise isolation and active noise cancellation? There’s a clear winner in terms of audio quality, comfort and battery life.



When you're shopping for earbuds, there are a lot of terms you see over and over. Two of those terms are passive noise isolation and active noise cancellation. If you're not sure what the difference is between the two, you're not alone. 


Though their goal is the same, passive noise isolation—also called passive noise cancellation— and active noise cancellation (ANC) couldn't be more different. And, for audiophiles, there's a clear winner in sonic quality, listening pleasure and comfort


In this article, we’ll explain the differences between passive noise isolation in terms of comfort, sound quality, ambient noise reduction and more. 




What is passive noise cancellation?


Passive noise cancellation (PNC) or isolation is when your headphones, earbuds, earphones, or in-ear monitors naturally block outside noise. In other words, your earbuds are isolating you from ambient noise instead of actively using technology to cancel it out. That’s why you’ll hear this technique called both passive noise isolation and passive noise cancellation. 


When your earbuds are molded to the exact shape of your ears, it prevents outside ambient noise from entering your ear canal. That means you can listen to music at lower volume levels because you don’t have to counteract the sounds of your environment—whether that’s a noisy coffee shop or the loud rumble of a plane engine.


You don’t need additional battery power to take advantage of passive noise isolation. All earbuds and headphones have some degree of passive noise isolation, but custom-fitted earphones, in-ears and earbuds are by far the best in this regard, as they create the tightest seal.


 Enter passive noise cancellation. PNC naturally isolates your ears from the outside world by sealing music in and the world out. ANC works by creating sound that phases out ambient noise.



What is active noise cancellation? 


Active noise cancellation is when your headphones or earbuds neutralize the ambient noise around you via noise cancelling technology. They work by incorporating microphones into your headphones, which listen to the outside noise and generate a phase-inverted sound that effectively cancels out ambient noise before it reaches your ears. In other words, ANC cancels noise by creating equal but opposite noise.


Unlike passive noise isolation, active noise cancellation requires a power source. You have to charge all ANC headphones and earphones to take advantage of active noise cancellation, which means those headphones most likely have a shorter battery life. 


Unlike passive noise cancellation, ANC is relatively easy to implement in earbuds and headphones. Great PNC requires a tight, custom fit to block ambient noise. ANC is a popular way for earbud manufacturers to offer some level of noise reduction without customizing the actual fit of their products. With PNC, it’s important that your earbuds fit your unique earprint.




Is active noise cancellation harmful?


Active noise cancellation isn’t harmful. There are no threats to your hearing with ANC headphones. There’s also no radiation or harmful waves involved in ANC technology. 


However, some people have reported feeling dizzy or anxious when using ANC headphones because there’s a constant hiss caused by the sound waves that the headphones use to cancel out ambient noise. If you’re particularly sensitive to sound machines or other white noise, you might want to avoid headphones and earbuds with active noise cancelling technology.


Many music lovers also find that they can’t listen to ANC headphones all day due to a phenomenon called ear fatigue. The equal-but-opposite sound waves created by ANC headphones to cancel out ambient noise also cancel out part of the sonic spectrum in your music. As a result, your ears need to work harder to fill in those blind spots, which can create the sensation of feeling like you can’t listen to music or wear your headphones as long.




Passive noise isolation vs. active noise cancellation


Now that you know the difference between passive noise isolation and active noise cancellation, you might be wondering which is better. Here are a few questions we’ve heard about passive noise isolation vs. active noise cancellation.



Which has better sound quality?


If you’re comparing two sets of earbuds with similar build and tuning quality, the earbuds with better passive noise isolation will sound better than the ones that rely on active noise cancellation to block out ambient noise. 


The reason passive noise isolation sounds better is because ANC earphones and headphones create noise to cancel environmental sounds. This effectively adds distortion to your music. Passive noise isolation results in a truer representation of your music while blocking outside noise.


PNC is trusted by musicians and music purists because it blocks ambient noise without adding noise or distortion. 


Which is more comfortable?


Passive noise isolation is best achieved through custom-molded and custom-fitted earbuds and earphones. Earbuds and headphones with active noise cancellation typically aren’t custom-fitted to your unique ears. That means your ANC earbuds will fatigue your ears more quickly because you’re putting pressure on certain parts of your ear more than others. 


With a custom fit, you won’t have to worry about pressure points. Earphones like UE FITS form to your ears, which makes for a more natural, comfortable feel. 



How effective is passive noise cancellation?


Passive noise cancellation and active noise cancellation each do a great job of reducing outside noise. However, each has its strengths and weaknesses depending on the range of the frequencies being blocked. 


Earbuds with passive noise cancellation can lessen mid- to high-frequency noises by about 15dB to 30dB. Meanwhile, active noise-canceling headphones and earbuds work better to reduce lower frequencies. That makes sense considering the technology was originally used for airline and helicopter pilots who deal with more low-frequency noise on a daily basis—not everyday music fans. ANC can cut ambient noise overall by an average of 30dB, while low frequency noise generated by lawnmowers, subway traffic and airplanes can be reduced by as much as 60dB.


In other words, earbuds with passive noise isolation reduce mid-high frequencies better while ANC does better with low frequencies.


Another thing to consider in regards to reducing outside noise is that ANC headphones work best at reducing constant background noise, not sudden transient noises. Sudden noises, like a car honking its horn outside your coffee shop, occur too quickly for your ANC headphones to detect and combat these sudden sounds. 


Meanwhile, passive noise isolation reduces all incoming sound by roughly the same amount. So ANC headphones won’t block out that car horn at all, but your custom-fit earbuds will reduce it as much as they reduce constant noise. 



Which is safer for your hearing?


While both passive noise isolation and active noise cancellation allow you to listen to music at lower volumes than earphones without ANC, passive noise isolation is better for your hearing overall. This is because active noise cancellation neutralizes outside noise by creating an equal and opposite noise. So, while you don’t have to crank the volume to hear your music as well, you’ll still have more decibels of noise entering your ears than you would with passive noise isolation at the same volume level. 



Which consumes more power?


Even if your passive noise isolation earbuds use Bluetooth to operate, they’re still consuming less power than Bluetooth earbuds with active noise cancellation. 


Earbuds and headphones with ANC require power to create the noise that cancels ambient sounds before they hit your ears. However, products like UE FITS only need power for the Bluetooth. That results in longer battery life, other elements considered. 


There are also earphones and in-ears like our CSX and PRO series that don’t use any power at all. With those options, you can enjoy high-fidelity sound and passive noise isolation without ever having to wonder if you remembered to charge them before boarding that six-hour flight.



Which is more affordable?


The cost of earbuds and earphones can vary dramatically depending on the brand. You can find earbuds with active noise cancellation for as little as $50, but the sound and build quality might be dubious. 


When you compare a product like UE FITS to earbuds with ANC that offer high audio quality, you’ll find that the prices are comparable between passive noise isolation and active noise cancellation. FITS are just $249, which is in line with ANC offerings from other reputable brands. However, no other off-the-shelf earbud brand offers customization for stellar passive noise isolation in 60 seconds the way UE FITS does.



Which is better when you're not listening to music?


If all you want to do with your earbuds is block out ambient noise, active noise cancelling earbuds may be a fine solution, especially if you mostly want to block out low frequencies. ANC earbuds can block out up to 60dB of lower frequencies, like sounds from subway trains. Keep in mind that active noise cancelling earbuds aren’t completely noise-free—you’ll still hear a gentle hiss from your earbuds’ noise floor. This noise always exists in ANC headphones, but is most apparent when you’re not listening to music but still have the active noise cancelling turned on.


If you want to keep earbuds in even when you’re not listening to music, custom-fitted earbuds like UE FITS will be more comfortable to keep in all day. That’s because earbuds like FITS form to fit your ears perfectly, so you won’t find your ears aching from pressure being unevenly distributed across your ear.



Which is more portable?


When it comes to earbuds, models with passive noise isolation are often smaller than those with active noise cancellation. That’s because active noise cancellation requires an onboard microphone in order to neutralize the ambient sounds. However, portability varies by brand and model of earbuds.




Are you ready to experience the immersive sound quality and unprecedented comfort with Ultimate Ears?


Back to Custom Made