Sometimes the world around us is simply too noisy to allow real enjoyment of your music. We’re going to see what to look for in head gear in order to beat the noise. Along the way we’re going to learn how some headphone technologies manage this.
The problem
These days I routinely measure equipment capable of signal to noise ratios of better than 115dB (A-weighted). But if you’re out in the street, the ambient noise level is perhaps 60dB, so the remaining dynamic range available to you is, at best 60dB, not more than 100dB.
Want to hear that fine detail, the subtle inflections in musicianship? No go.
Even in many homes there’s a certain level of ambient sound that can mask fine details.
There are two approaches to the problem. One is to just turn up the music louder. That’s not necessarily good for the performance of your system, for your ears, or if you’re using loudspeakers, for your relationships with your neighbours.
The other is to reduce the noise. And since you’re generally not able to place roadblocks across nearby thoroughfares, you’re going to have to do the blocking locally.
Very locally, by using well-chosen earphones or earphones.
Headphone and earphone strategies: active and passive
Both headphones and earphones have adopted one or both of these strategies – passive noise isolation or active noise cancellation – for dealing with the noise in the world around you.
The most common is passive. Don’t like what you’re hearing around you? Try sticking your fingers in your ears. That will reduce the level considerably.
Of course, your headphones or earphones can’t completely do that. They do, after all, have to let in the music. And no noise isolating technique is perfect. But passive headphones and earphones can reduce the amount of noise that makes it in from the outside by quite a lot. On this front, earphones – in particular “in-ear monitors”, or IEMs – are most effective.
Active noise cancellation is a relatively recent innovation. The first consumer ANC headphones appeared in the late 1990s. These work by generating an active signal which defeats some of the noise which would otherwise make it through the headphones into your ears.
Let’s dig into these in a bit more detail.
Passive noise isolating headphones
This is the obvious and traditional way of providing some protection from the noise around you to better enjoy your music. Since you can’t just stick your fingers in your ears, passive devices attempt to seal off your ears from the surrounding noise while providing the music.
In the case of headphones, that means closed-back headphones, and almost always over-ear headphones. Obviously, open-back headphones allow outside sounds to pass straight through to your ears. On-ear headphones simply don’t seal off your ears as well as over-ear headphones.
These headphones need to be worn properly for maximum effect. If the arms of your reading glasses, for example, break the seal between the earpads and the area of your head surrounding your ears, additional external noise will be admitted.
How effective passive headphones prove to be depends very much on their design, fit and construction materials. Some are designed with a particular focus on isolating you from outside sounds, for example DJ headphones.
The best way to judge which passive noise isolation headphones best suit you are to visit a quality retailer of headphones and try some on for size and sound. Remember, you don’t just want the best noise isolation, you want fine sound quality to go with that.
Pros of passive noise isolating headphones
- Some offer superb sound quality
- No batteries or charging required
- Easy to use
Cons of passive noise isolating headphones
- Not as effective at beating noise as active headphones or the best in-ear monitors
Our top picks for noise isolating headphones
Fostex T40RP Mk 3 – $199
Focal Elegia – $799
Astell&Kern AK T5p (2nd Gen) – $1699
Passive noise isolating earphones
This may seem surprising, but passive noise isolating earphones, if done right, can be markedly more effective at stopping outside noise than passive noise isolating headphones. Some can achieve noise reductions of up to 50dB in the upper midrange areas to which our ears are most sensitive. One manifestation of this has been the gradual adoption of this kind of earphone – often called in-ear monitors or IEMs – by live performers, instead of using on-stage foldback monitor speakers.
The main key to effective noise isolation is achieving an complete seal between the earpieces and your ear canals. Do that, and it really is like putting your fingers in your ears.
The earphones or IEMS must be inserted into the outer part of the ear canal to achieve an effective seal.
Soft tips are required for an effective seal. One of the mysteries of this business is that it took Apple so very many years to realise that its hard-plastic earpieces were a terrible bit of design. Most commonly the soft tips are silicone, a rubber-like material that is relatively non-allergenic and somewhat more durable. Tips can be of various shapes and are frequently verging on spherical. But some feature multiple flanges for increased noise isolation.
However, for my money the most effective noise isolation comes from earphones featuring “Comfort” or memory foam tips. We shouldn’t be surprised by this, given that earplugs are frequently made of memory foam.
Again, performance will depend heavily on proper use. Fortunately, you will see hear and feel the difference between having achieved a good seal and not having quite managed it. With earphones and IEMs, not only does noise isolation depend on achieving a good seal, so does effective bass performance. Any leaks and bass, especially the deeper bass, immediately loses its strength and impact.
With silicone tip earphones, I find it best to kind of screw them in. I place the tip into my ear canal with the wired connection pointing out in front of me, and then with a steady inwards pressure applied, rotate it a quarter turn so that the cable points directly down. Then maybe wiggle it a little more if it doesn’t feel quite right.
With memory foam tips, the technique is quite different. I hold the right earpiece in my right hand, then squeeze the tip into a thinner cylinder using the thumb and first two fingers of my left hand. Then I quickly place the tip as far into my ear as it will go, with the earphone in the final position I’d like, and wait a few seconds as the memory foam attempts to return to its former volume. Within a few seconds I feel the quiet descending as the tip fills my ear canal.
Pros of passive noise isolating earphones
- The best passive noise isolation, challenging the best ANC models
- Extremely high quality sound available from some models
- No batteries or charging required
- Compact and easily transportable
Cons of passive noise isolating earphones
- Not everyone is keen on having earphones in their ears
- Generally a bit fussier when donning and removing earphones compared to headphones
Our top picks for noise isolating earphones
Final Audio A4000 – $249
FiiO FD5 – $459
Noble Tux 5 – $2099
Active noise cancelling headphones
Active noise cancelling headphones don’t just try to block out noise. They listen to the noise and actively counteract it.
Let’s take a moment to understand how this works. Active noise cancelling headphones (there are ANC earphones as well) have one or more microphones on the outside of each of their earcups. These microphones capture the sound of the world around you. Then they invert the waveform, process it and feed it into the signal that you’re listening to. Your headphones then reproduce that sound, mixed in with the music. When a sound is combined with the flipped version of itself, the two waves destructively interfere with each other, cancelling each other out. So, in theory, you will hear neither the outside noise that has made its way through the headphone housing, nor the cancellation signal.
In practice, there are compromises and inaccuracies. For one thing, the noise that the microphones capture on the outside is not the same as the noise that makes it through the housing. Active noise cancelling headphones are closed, of course*. That way they can get a head-start on the noise reduction through a bit of good old passive isolation.
So, the sound has to be processed so that it matches, as closely as possible, the sound that makes it into the interior of the earcups. This is necessarily approximate. Some models also use internal microphones to provide more information for the processor. And the processing has to performed incredibly quickly.
In addition, there are physical limits on the drivers which are likely to be exceeded with too aggressive noise cancellation in the bass, so it’s most effective in the midrange and high frequencies.
Nonetheless, some of the better active noise cancelling headphones can reduce noise by 40dB.
One other thing to remember: active noise cancelling headphones are just about always Bluetooth models (although the early models were wired). Most come with a cable so they can be used wired, but the cable typically feels like a low-cost afterthought. Audiophile performance may well be limited.
Indeed, since the sound is being processed, with additional material being inserted into it, it’s actually pretty astonishing that active noise cancelling headphones can sound quite good.
Pros of active noise cancelling headphones
- Highly effective noise reduction
- Bluetooth convenience
Cons of active noise cancelling headphones
- Employ a great deal of signal manipulation which can affect sound quality
- Have to charge them up
Our top picks for active noise cancelling headphones
ag WHP01K – $149.99
FiiO EH3NC – $299
Bose QC35 II – $499.95
Which one is best for you?
There is no real hard and fast rule for choosing amongst the options here. Headphone and earphone choice is a highly personal matter in all ways, including fit, comfort, a secure feel on the head, sound quality and features.
Not all passive noise isolation works the same. Not all active noise cancellation works the same. The latter, in particular, has gotten much better over time, but there are still plenty of headphones and earphones where the active noise cancellation has very little effect.
However, broadly speaking, if you’re travelling a lot by air and you want just one set of headphones, then a quality set of active noise cancelling headphones are the way to go. Look for ones with a long battery life if your travel includes international flights.
But if the very best quality sound is the highest priority for you, then passive is probably also the best for you.
* Fun fact, the first active noise cancelling headphones for consumers were released by Sony in 1996 and 1997 – yes, well ahead of Bose. There were three models. One of them – the MDR-NC05 – actually were open-backed. I don’t think they lasted long.
