Whether you need to buckle down and get on with site work, do some DIY or even simply mow the lawn, noise cancellation tech can make work, hobbies and chores a whole lot more pleasant.
Avoiding noise can also reduce stressors or overstimulation, which is why there are ear defenders for autism as well as for work or travel.
These headphones can utilise one (or more!) of 3 types of noise reduction technology and today I'll breakdown exactly what those 3 types are, and how they work.
Hopefully, you'll find the right balance of noise cancellation for you!
The 3 Types of Noise Cancellation
So, what exactly are the 3 types of noise cancellation?
Passive Noise Cancellation
Passive noise cancellation is the easiest type of noise reduction technology to understand. In fact, it's barely "technology" at all as it requires only one component, and no electronics at all!
If you've ever heard a loud siren, fire alarm or such which constantly assaults your ears, you might have found yourself covering your ears with your hands or arms, or even quite literally putting your fingers in your ears!
Physically obstructing your ears with a barrier is the core principle of passive noise cancellation.
That's all there is to it.
Because sound is just the specific movement and vibration of particles in the air as a wave, stopping those waves from reaching your ear will of course negate the sound!
In reality, passive noise reduction doesn't insulate 100% of those waves, instead slowing them down, absorbing their energy and "reducing" them to lower levels of energy. This means that by the time the waves reach your ears, they are far less loud than they could have been.
Passive noise cancellation can be identified by large, padded earpieces on headphones, or silicone insulating earbuds in earphones. These elements insulate your ears from sounds outside, and provide better sound from the speakers within that physical barrier.
Active Noise Cancellation (ANC)
Active noise cancellation is more often simply called ANC.
The reason ANC is called "active" rather than the previous "passive" technology, is that the headphones will use microphones facing outwards, away from your ear, to actively "listen" to noises around you.
The cancellation is changing every single moment to account for changes in volume and pitch of your background noise, making it much more engaged in the noise reduction process than a simple piece of padding. Hence "active".
ANC microphones "hear" background noises around you, like traffic. The sound of the traffic will have a specific volume and pitch (Defined by the amplitude and frequency of the sound wave). The microphones pass this information instantly to the speakers, which play a "counter-tone".
A counter tone does exactly what it says, it counters the sound of the traffic. By playing a sound that has the exact amplitude and frequency, but inverted, the headphones can cancel out the sound wave from the traffic and eliminate the noise from reaching your ears!
There's some variance as microphones detecting the sound are not 100% accurate, the speakers creating the counter-tone are not 100% accurate, and the background noise will rarely be one consistent sound but instead many overlapping ones.
That's not to say ANC is useless, I am just reiterating that while the technology can, in theory, eliminate a sound wave entirely, it is not possible in practice for the majority of noises. Instead, the noises will be much reduced and nigh unnoticeable under your music, but still technically there.
Digital Signal Processing Noise and Echo Reduction (DSP)
Digital Signal Processing (DSP) noise reduction is the final type of noise cancellation tech you'll find in Bluetooth ear defenders, headphones and earphones.
Specifically, DSP can be present in devices which have a microphone for taking phone calls / using voice assistants.
DSP is different to the previous types of reduction as it doesn't actually affect what you hear at all!
"What?" I hear you ask, "What's the point then?"
Well, DSP is a digital process that refines and filters recorded sound as it is sent from your microphone to your phone call! This means that the person you're calling can hear your voice more clearly, without them themselves needing noise cancellation.
DSP works to reduce echo and background noise between your end of the call and theirs, so it's actually your caller who receives the benefit of DSP, not you as the wearer!
Technically, there are some cases where DSP does affect the wearer if they are listening back to the recording in real time, such as streaming and hearing the on-stream audio simultaneously. But, for the most part DSP is feature that enhances phone calls rather than helps you block out the world with headphones on!
How to Judge Noise Cancellation
With a thorough understanding of the 3 types of noise cancellation, now you need to actually see how they stack up on different products! How can you identify how "good" the noise reduction is for one pair of noise cancelling ear defenders to another?
Single Number Rating (SNR)
The simplest way, and the way most manufacturers will show, is the single number rating or SNR. This is a measurement average in Decibels (dB) which is intended to show you the flat amount of sound reduced.
For example, if wear 30dB SNR headphones near an 80dB motorway, the effective volume of that motorway to my ears is 50db.
There are some restrictions when it comes to SNR, such as maximum volume limits (i.e a 150dB sound won't be reduced almost at all), but in general use it's the best and simplest way to quantify noise cancellation.
Choosing a Pair of Ear Defenders
The best ear defenders for you will depend on your use and how long you want the battery to last. These are the main factors for choosing between the different styles.
A pair of ear defenders with no ANC, instead built around purely passive noise reduction will have a far, far longer battery life than a pair with ANC. ANC drains battery to power the microphones and play the counter-tone, while passive noise reduction is all in the engineering and physical construction of the headphones.
Passive Vs Active Noise Cancelling Headphones
For working on-site, contracting, and using for full 10-hour work days we recommend a passive noise reduction pair of ear defenders for that maximum battery life.
The August EP120's that came out over Christmas last year (For 'tis 2025 now) can reach 120 hours of working time per charge, because they aren't using ANC and the audio volume can be lower than usual, as the sound is insulated so well.
They are Bluetooth ear defenders, so use some battery to work wirelessly, but at 120 hours I don't think that's much of a hit!
However, for short bursts of use like doing the garden mowing or reacting to suddenly overwhelming situations for a person with auditory sensitivity, an ANC pair will reduce more sound and be more helpful.
You do sacrifice the battery life, however, and the digital jumping of ANC working can actually be more upsetting to those who are hyper-sensitive to sound, as the counter-tone may be unexpectedly heard.
Are Ear Defenders for Adults?
In looking at this topic I discovered a swathe of people who were interested in noise protection for infants or babies, but unsure if such a thing existed for adults. It surprises me as my first thought when I consider noise reduction tech is a burly man on a construction site, but I suppose we're all different and have different connotations.
Suffice to say, ear defenders are perfectly suited for adults, too.
Everything You Need to Know About Noise Reduction
I hope you've picked up the basics of noise reduction here, and can better understand how the 3 types of noise cancellation technology play a part in creating ear defenders for construction work, hobbies and more.
Remember to keep an eye out for passive noise reduction, ANC and DSP as you shop around for a pair of headphones or earphones; the best noise cancelling headphones will do all 3!
Just remember not to sacrifice battery life for fancy effects if you're going to be using the headphones for long hours.
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