If you like to while away the hours by listening to music via your headphones when you're on the go, you may be intimately familiar with the following annoyance—no matter how hard you try to ignore it, ambient noise is always there, in all its distracting glory. Fortunately, there's a solution—active noise-cancelling headphones that can filter out ambient sounds. How does Active Noise Cancellation (ANC) work, what does it offer and what are the potential risks? We'll also take a look at the best noise cancelling headphones currently available.
The basic principle of ANC technology–Active Noise Control or Cancelling–is essentially simple. It consists of cancelling out unwanted sounds by putting other sounds in the way to eliminate them. To eliminate unwanted noise, it uses the same sound amplitude (sound is a pressure wave) as the noise source, just at the opposite frequency. When the two waves meet, they cancel each other out.
Repetitive droning noise is easier to eliminate. Basically, you could say that this gives the system time to "recognise" the sound amplitude and create the opposite frequency. By droning noise we mean the distant hum of a crowd, typical noise on a busy street, or vehicle engines. A honking car horn or an ambulance, however, present a bigger challenge.
Active Noise Cancellation works best at lower frequencies (i.e. the normal hustle and bustle and the fuzzy ambient noise that surrounds us virtually all the time). However, it finds its use not only in headphones, where this technology is probably the most talked about, but also in hands-free microphones, air conditioners or in larger spaces such as subway platforms. The purpose is the same in all cases—to reduce the effect of unpleasant noise on human hearing.
ANC technology works on the basis of an added microphone that senses ambient sounds, evaluates them and then adds a signal with the opposite frequency to the sound stream.
Active Noise Cancelling technology is designed to help you enjoy your media in peace, but it also has one positive side effect. This benefit is indirect: By cancelling out distracting ambient noise, we can play music in our headphones at a significantly lower volume. Because if we want to drown out (not cancel) the ambient noise in the old-school way, we have increase the volume, and prolonged exposure to loud sounds can cause hearing damage. Moreover, the damage is accumulative and may take many years to manifest.
ANC headphones do not emit any harmful electromagnetic waves into your ears or brain—which is also the argument of those who reject them. It's always just another sound wave. The fact that we are not making things up can be heard in cheaper ANC headphones: in moments of silence, you can hear a subtle background noise. ANC headphones are therefore perfectly safe to wear.
However, an indirect consequence of ANC headphones may be that when you eliminate ambient noise, you may no longer hear the sounds that you generally do want to hear: an audio warning at a pedestrian crossing, an approaching tram, an ambulance, or an announcement at a train station. But as we wrote above, ANC headphones don't dampen sudden noise as easily, so you shouldn't expect 100% noise isolation at any rate. At the same time, some models of headphones (see below in the section on specific products) offer a choice of multiple levels of noise cancellation. And when you choose one that's designed for walking down the street, you can rest assured that your ears will still get exactly the sounds they need to. Different manufacturers call this technology differently, from Apple's Transparency mode to Sony's Ambient Sound.
In any case, there's no harm in keeping your other senses sharp. Look around you, look both ways when crossing the street, and stay aware of your surroundings to keep yourself safe when enjoying your favourite music. We also recommend removing the headphones in potentially risky situations, for example at a busy intersection.
Headphones can be divided into several categories, each of which is suited to something slightly different. The key factor is their purpose. Are you looking for mobile phone headphones to use on the go or for comfy home listening from various sources?
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A special sub-category of wireless headphones are True Wireless. These are completely wire-free, ensuring maximum user comfort.
Noise cancellation technology is also used in the more sophisticated earplugs (commonly known as "wireless sleep headphones"), i.e. the plugs we use at night to help us sleep better. They work on two levels - they create a physical barrier to sound entering our ears, and in addition they create a Noise Cancelling barrier for those sounds that do get through. For example, the aforementioned constant hustle and bustle of the city, which we may no longer consciously perceive, but it's still a source of distraction to our brain. Moreover, some types of headphones for sleeping not only muffle the outside noise, but also replace it with specially chosen soothing sounds that help us fall asleep more easily. The Noise Masking Sleeping Buds from Bose do just that.
Now let's get to a brief overview of the top five most interesting ANC headphones you can find on the market this year. You won't go wrong by buying any of them.
The first on our list are the Sony Hi-Res WH-1000XM4 headphones. Sony noise-cancelling headphones deliver a truly high-quality experience. They are the latest iteration of the popular and highly rated older models and further develop what we've always liked in these headphones. They feature a clean design in multiple colours and a touch pad on the earcups. These are cushioned, helping to isolate ambient noise while remaining comfortable on the ears even after hours of playback. Inside are 40mm drivers that can easily handle high-resolution audio.
With ANC on, the Sony Hi-Res WH-1000XM4 headphones last up to 30 hours of playback on a single charge, and six hours more without ANC. Charging via USB-C will deliver 5 hours of additional listening time in 10 minutes. For signal transmission, the headphones use Bluetooth 5.0 or NFC technology. Hands-free call support is available, complete with HD Voice or Echo Cancellation technologies.
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Great headphones for travel include the JBL Everest Elite 750NC.
With Apple AirPods Max Apple has finally ventured into the realm of large over-ear wireless headphones. And it was an instant success. The combination of advanced technology and unmistakable design goes hand-in-hand with excellent sound. The wireless headphones are made in a combination of stainless steel and aluminium and have telescoping arms to find the perfect fit with their large earcups. These are made up of breathable fabric and plenty of memory foam and conceal dynamic 40mm drivers.
In addition to ANC, the wireless headphones have 7.1 surround sound and the battery lasts 20 hours on a single charge. After that, it only takes 5 minutes to charge them up for another 90 minutes of playback.
The name of the Bose QuietComfort 35 II wireless headphones tells you exactly what to expect. Thanks to their advanced ANC system, you can enjoy real peace and comfort. The level of ambient noise cancellation is adjustable and there are three levels of intensity to choose from.
The wireless headphones also look good and can take a lot of punishment. They are made of shock-resistant materials and have a highly durable stainless-steel frame. They can also withstand some mild water splashes. And to top it off, the Bose noise cancelling headphones are among the most comfortable on the market and don't get heavy even on long flights. Google Assistant voice control support is also worth noting. With the headphones on, you can ask for navigation when you happen to get lost, for example, or have your phone in your pocket place a call remotely. The function is activated by pressing a button on the left earcup.
Reliable ANC isn't exclusive to large over-ear models. This is amply demonstrated by the unobtrusive Sony True Wireless WF-1000XM4 earbuds, which are among the best of what the True Wireless headphone segment can offer. The 6mm drivers combined with the brand new V1 processor offer crystal-clear audio, protected by high-end ANC against external noise. The Sony noise cancelling earbuds are lightweight and, thanks to the sophisticated ergonomics, fit well in the ear and do not fall out even during exercise. They are also IPX4 certified, which means they are resistant to dust, sweat and water splashes.
The Sony noise cancelling headphones last up to 36 hours with ANC off (12 hours headphones + 24 hours with the case); with ANC on you should expect about half the battery life. The case supports wireless charging. Bluetooth 5.2 with support for AAC, LDAC and SBC codecs takes care of stable connectivity and, as Sony models tend to, the headphones also support Hi-Res audio.
The last headphones on our list are JBL Live 650BTNC. This model also features noise cancelling, which protects the listener from distracting ambient noise. There's also the Ambient Aware function to keep you abreast of potential hazards on the street. The JBL wireless headphones offer high-quality audio and are foldable. A full charge takes two hours.
Active Noise Cancelling (ANC) is a useful feature in modern headphones. You'll use it practically every day. Now you don't have to crank up the volume to deafening levels just to hear something on a noisy subway. ANC is there to eliminate the annoying noise for you.