Active noise-cancelling headphones exist to eliminate annoying outside noise so it doesn’t ruin your music listening or distract you from work. Learn how active noise cancellation works in detail and many practical ways how to use it in everyday life. CONTENTS (show more) What are Active Noise Cancelling Headphones? Active noise-cancelling headphones use microphones and chips running complex algorithms to eliminate unwanted noise. More on that below. What makes them different from passive noise-isolating headphones is that the latter only passively block external noise without the use of electronics. They rely on soundproofing from unwanted background noise with thicker earpads and ear tips with deeper insertion. ANC headphones do the same and add active noise cancellation. The ANC headphone market is constantly growing because it’s getting cheaper and people are recognizing the increase in noise pollution. Noise-canceling headphones are a popular commuting accessory. Furthermore, ANC technology isn’t as expensive as it was decades ago when it was mostly popular among aircraft pilots. Today anyone can afford at least basic ANC headphones. Since even modern ANC still struggles with higher frequencies, most headphones combine good passive noise isolation (it’s false to call it “passive noise cancellation”) and ANC (active noise cancellation). Passive isolation reduces upper midrange and treble frequencies, whereas ANC reduces lower mids and bass frequencies. How Active Noise Cancelling Headphones Work Active noise cancellation works by playing the inverted signal (a sound wave) of the noise you want to cancel into your ears. It uses dedicated electronic chips (DSPs) to process complex algorithms that create the inverted signal in a split second. This is also called “creating destructive interference”, but more on that later. In order for this to work optimally, headphones require at least one built-in microphone per earcup, either internal or external or both, to successfully eliminate noise. Every ANC Bluetooth headphone has a separate DSP chip to process the recorded audio. How ANC headphones use microphones As mentioned, ANC headphones use microphones to capture surrounding noise before it gets processed. You need at least one microphone per each side for noise cancellation to work effectively. The more you have, the better. External microphone captures the noise from the outside. Internal microphones “listen” to the noise that still passes through the ear cups/earbuds and analyze how the headphones fit you to adjust the ANC. You can separate ANC headphones based on how and how many microphones they use in 4 groups. More on that under the types of ANC headphones. Creating silence with destructive interference Destructive interference is an acoustic phenomenon where you create an equal and opposite signal of the original one to cancel out both signals. The original and created signal need to be identical in frequency and loudness (amplitude). By “creating an opposite signal”, we mean inverting the signal’s phase. How active noise cancelling works in visual representation. source: Analogictips DSP then creates the opposite signal (an “anti-noise”), which is played back into your ears through headphone drivers. When the ambient noise and inverted signal meet in your ear canal, they cancel each other out. Algorithms and DSP make a difference All of the processing needs to happen in a split second; otherwise, it doesn’t eliminate the noise. ANC chips rely on complex algorithms to create the most accurate copy of the outside noise. Whatever audio microphones capture needs to be processed and reconstructed to match real-life noise as accurately as possible. It’s very difficult. Algorithms predict how the noise will behave and try to create a perfect copy. DSP then applies those changes to a captured noise and inverts its phase. Though, that doesn’t always work. Even with the best ANC headphones on the market. Despite having active noise-cancelling technology for decades, manufacturers still can’t fully cancel out certain frequencies. The easiest external sound to actively eliminate is a constant low-end hum. On the other hand, rapidly changing or sudden noises like human speech or barking are the most difficult to cancel out. Benefits of Active Noise Cancelling Headphones & Earbuds Some people tend to think that active noise cancellation is a redundant feature. However, almost all will find it extremely useful at least once. Here are all the ways ANC can make your life better. Listening to music with or without hearing ambient noise is a night/day difference. An immersive listening experience If you’ve ever traveled via public transport or plane, you know how loud and distracting engine noise is. When listening to music, low-frequency hum overpowers the sound, masking details and ruining your immersion. Enabling active noise cancelling reduces the hum to almost inaudible levels. It leaves you just with your music. If you haven’t tried it, it truly makes a night and day difference. Safer listening The logic here is that when listening to music in noisy places, you tend to raise the loudness to mask the noise. But that can be dangerous. Listening to a sound of 100 dBA (decibels) for 2 hours can cause damage, according to OSHA (Occupational Safety and Health Administration). Always practice listening to headphones at safe loudness and try some of the tricks mentioned in the linked article. Effective noise reduction can protect your hearing. When you reduce ambient noise with active noise cancelling headphones, you don’t raise the loudness as high. Consequently, protecting your hearing. If you have doubts regarding ANC and its safety, we made a science-based article on this topic. Less stress for ears Loud ambient noise can have a negative effect on your health. It can spoil concentration and raise your stress levels. These, over time, lower your immune system and sleep quality, among other things. Using active noise cancelling to reduce unwanted sound is a potential solution to combat noise-induced health problems. Apart from living in a noise-free environment as a much better long-term solution. Limitations of ANC Headphones & Earbuds While truly useful, active noise cancellation has drawbacks. At least until the technology doesn’t get better. Here are ANC’s biggest limitations. Low effectiveness for some frequencies Active noise cancelling algorithms need to predict how much of the outside noise will come into your ears. Low-frequency sounds can pass through almost unchanged, and the shape of your ear canal also doesn’t affect them, so they’re the easiest to predict and eliminate. ANC works best when canceling out low-end frequencies. On the other hand, high-frequency sounds are more easily blocked passively but also change when inside your ear canal. This makes it harder to predict their loudness and, thus, harder to eliminate with a generated opposite sound. Some headphones play a start-up tune when you turn them on, which acts as a calibration for your ears. But even this isn’t always working. That is why you often hear a faint white noise when using ANC. Higher battery consumption Using algorithms and a DSP chip to process the recorded signal requires a lot of energy. Just a few years ago, ANC used half of the battery. Combined with the already low battery durations of Bluetooth headphones, you were forced to use the feature only when necessary. Today, active noise cancelling uses around a third of the battery life, which is still a lot. However, batteries are also better now, so you can keep ANC turned on. Modern Bluetooth ANC headphones are getting better at battery durations, but the toll is still too high. Bad performance in certain environments Some manufacturers of Bluetooth headphones decided to make the headphones sound better when you use active noise cancellation. However, that means that when you turn ANC off, you get a worse sound quality. The wind is a problem. Using ANC headphones outdoors is never a good idea due to wind noise. The wind noise you produce by walking is quickly picked up by microphones and played into your ears, which is incredibly distracting. Potential safety hazard Some people experience negative effects of active noise canceling, such as: In-ear pressure sensation, which is essentially your brain’s interpretation of the lack of low-end frequencies, can make you nauseous or causes a headache. A lack of awareness of what’s happening around you can be dangerous if you walk near a busy road and can’t hear passing cars. One solution is to use headphones with adjustable ANC that pass through important noise while blocking the other. Some people experience dizziness when using ANC. Types of Active Noise Cancelling Headphones There are 2 main types of noise-cancelling headphones: active and adaptive. Active noise cancelling headphones maintain the constant strength of the noise cancellation. Adaptive noise cancelling headphones regulate the strength of the noise cancellation based on the ambient noise. Active noise cancelling headphones again separate based on the number and functionality of the built-in microphones: Feedforward ANC headphones only use the external microphone to capture surrounding noise. Such ANC is the least effective, as it can’t self-correct itself by using internal mics. Feedback ANC headphones only use an internal microphone. It better hears what you hear, but it still doesn’t work the most effectively. Hybrid ANC uses both external and internal microphones to hear the surroundings and to self-correct itself using the internal mic. ANC headphones also arrive in different designs, such as over-ear, on-ear, and in-ear. Over-ear headphones, especially with thick ear pads, offer good passive noise isolation, which works well in combination with active noise cancellation. Meaning they’re very effective at reducing ambient sounds. On-ear headphones only partially cover your ears, leaving some gaps for the external noise to get in. Consequently, there aren’t that many on-ears that offer ANC, apart from Beats Solo Pro. In-ear headphones seal off the ear canal directly, making them the most efficient at passive isolation. Combined with deep eartips and a good ANC, you can barely hear anything around you. Unfortunately, not many in-ears have satisfying ANC performance. Classic earphones can also have ANC, as seen in SoundPEATS Air4. However, it works poorly due to already poor passive noise isolation. Different Noise Cancellation Modes in Headphones Previously, we already mentioned adaptive ANC and how it changes its intensity based on the loudness of environmental noise. True wireless Anker Soundcore Liberty 3 Pro have ANC like that. Some headphones offer different noise cancellation modes to switch to, depending on the situation. Numerous active noise control settings inside the Soundcore app for the Anker Liberty 3 Pro. For example, Anker Soundcore Life Q35 offer Transport, Indoor and Outdoor modes. Each mode prioritizes different frequencies that it has to eliminate. Transport focuses on a broader frequency spectrum to combat engine noise and people’s speech. Indoor targets people’s speech above anything else, as it’s best for use in the office. Outdoor tries to reduce traffic and wind noise. How to Get Better Noise Cancellation in Headphones & Earbuds While you can’t tweak the algorithms themselves to improve the active noise cancelling performance, there are a few things you can try for optimal ANC. 1. Get a proper fit/seal Headphones, especially true wireless earbuds, need a good seal to provide the best ANC experience. Some headphones with hybrid ANC, like Sony WF-1000XM5, don’t enable ANC if they can’t detect a proper seal. The most important thing for ANC to work is to get a proper seal. For over-ear headphones, ensure that earpads fully enclose your ears. The plusher the earpads, the better. If you have had them for over a year and feel like the pads are stiff, you might want to change them. For in-ear headphones, see that you’re using ear tips that provide good isolation even without enabling ANC. If the bass is a little weak, you probably don’t have a sufficient seal. Here’s how you wear every headphone type accurately and comfortably. 2. Update firmware One of the useful things about headphone mobile apps is the ability to keep your headphones bug-free and to intentionally improve performance, including ANC. However, in 2022, Apple AirPods Max received an update that downgraded their ANC performance due to some legal problems. So, updates sometimes make it worse. What brands have the best ANC headphones & earbuds? Brands that offer top-of-the-line ANC performance are: Apple Sony Bose Edifier EarFun Over recent years, we’ve tested many ANC headphones and earbuds from various brands and got mixed results. However, the brands above have consistently surprised us with their ANC effectiveness. While flagship Apple, Sony, and Bose ANC headphones are pricey, you can pay less than $100 for outstanding ANC from Edifier and EarFun. However, there are other good ANC brands worth checking out. That’s why you should check our ANC tests and guides to find the top options: Best ANC headphones: Get some of the best budget noise-cancelling headphones under $80 if you really want to save money. Check the best ANC headphones under $100 if you want a more affordable yet still great solution. See the best ANC headphones on the market if you want “crème de la crème” performance. Best ANC earbuds: Browse among the best ANC earbuds if you want smaller, more discrete headphones. FAQ: Frequently Asked Questions About ANC Headphones & Earbuds Do ANC headphones cancel all noise? ANC headphones don’t cancel all noise, at least not with current technology and algorithms. They’re the most effective with low frequencies and constant noises. Is it safe to wear noise cancelling headphones? It is perfectly safe to wear noise cancelling headphones in regards to hearing health. On the other hand, it isn’t safe to wear ANC headphones near busy traffic since you can’t hear potential dangers. What’s the difference between ANC headphones and regular headphones? ANC headphones use passive and active noise cancellation to reduce ambient noise, whereas regular headphones only rely on passive noise isolation. Do active noise cancelling headphones work without music? Yes, active noise-cancelling headphones work without music. You can use them just to reduce loud noises without music. Are headphones better at noise cancellation than earbuds? Earbuds are overall better than headphones at noise cancellation as they already achieve better passive noise isolation. Do Sony WF-1000XM4 earbuds have better ANC than Sony WH-1000XM4 over-ears? No, the Sony WH-1000XM4 have a better ANC than the Sony WF-1000XM4. They’re just a tiny bit more effective at reducing human speech. Conclusion Active noise cancellation headphones are a perfect solution for the loud world we live in. Even someone who generally doesn’t use the feature, finds it useful when going on a bus, train, long trip, or when trying to concentrate in a noisy place. That said, not all ANC headphones work the same, so you have to pick the right ones to get the best experience. Fortunately, you can find excellent options even below $100. Best ANC headphones: Best budget noise-cancelling headphones Best ANC headphones under $100 Best ANC headphones Best ANC earbuds: Best ANC earbuds Peter SusicFrom a childhood fascination with sound, Peter’s passion has evolved into a relentless pursuit of the finest headphones. He’s an audio expert with over 5 years of experience in testing both audiophile and consumer-grade headphones. Quote: “After many years, I can confidently tell which headphones are good and which are terrible.” Find his honest opinion in his reviews.