Home > Consumer Reviews > Sony MDR-NC40 High Quality Noise Cancelling Headphones

First off, I have to say that these headphones sound absolutely amazing, well worth the price if its sound quality you're after. They take a few hours to get used to. To begin with the noise cancelling feels a bit weird, like your ears have popped but you soon get used to it. The noise cancelling gets rid of droning or humming sounds like engine noise on a plane very well, but isn't so good at filtering out irregular noise like speech or background music.

Battery life is brilliant. I use these for about 2 hours a day and on average i only need to change the battery once a week. (I use 700mah rechargeable AAA batteries.) There is a little pocket in the carrying case for a spare battery as well as the airline adapter. One annoyance is that I often forget to turn off the headphones when I'm finished with them. The power indicater is quite dim, I suppose so that its unobtrusive in the dark but it makes forgetting to tun off the headphones a regular occourence. This might just be me though, as I'm quite a forgetful person. The headphones fold up neatly into the case. I've found that the best way to do this is to fold up the headphones, put them into the case, coil the wire and battery box around your hand, slip that off your hand and stuff it into the leftover space in the pouch.

Sound is simply amazing. If you're used to small, in-ear headphones then these might sound like there's no treble at all, but one you get used to these you'll wonder how you could ever put up with small in-ear headphones. Bass response is ample without sounding boomy. A warning, as the battery wears down the bass response deteriorates and overall the headphones are a lot quieter. It is possible to use the headphones passively, that is to turn off the noise cancelling, but the headphones sound very tinny and cheap if you do this. even in situations where noise cancelling isn't required I recommend that you turn on the noise cancelling, just to improve the overall sound.

Build is classic Sony. Well made and thought out but conservative. They dont shout out that they're anything special; they just look like your average pair of travel headphones. If I was picky i could say that the headband is a little flimsy. I wouldnt recommend storing them unprotected, keep them in the case when you're not using them. The cable is long enough but not too long. The plug is gold plated, not that it makes any discernable difference to sound quality but its a nice touch.


Overall an excellent pair of headphones but a little expensive. Well made, excellent sound and excellent battery life.

I bought these to reduce noise on long air travel. I use them purely for canceling background noise. I have not been using them with any MP3 player or the like.

They do work. There is a big difference between when they are turned on and not - when they are turned on, they reduce the background noise quite a bit. They just don't reduce the noise enough for me.

I think I will go for another product - probably twice the price - I have tried a more expensive unit - also from Sony - borrowed from a friend. They worked much better.
I guess this just proves the old saying: He who buys at half price ends up paying double.

I do like the small form factor on this headset. They are nice for what they are.

Well, being portable head phones, you can't expect these to be of the same quality as more expensive 'non portable' head phones.
That said, I find them to be a welcome relief from the annoying big printing machinery behind me and the endless drone of my colleagues talking. Note that it cannot get rid of all sound, that's not what these are about, but it will significantly reduce sound and eliminate the continuous frequency sounds. Note too that the noise is cancelled out by a mic in the headphones that then gets processed and an opposite sound sent out. That means if you are running, you will HEAR it.
On a plane, turn on the switch, and the relentless drum of the plane's engines is cancelled out almost entirely. Turn on my tunes and dream the flight away. If that doesn't take your fancy, watch an in flight movie. No more waiting to buy head phones for that, or folking out the £5 for head phones just so you can use the adaptor. As using the supplied aeroplane adapter, you're already set! Yet another perk.
Put all of this together with a well designed leather holder and you have a great package for a great price.
Top class for the value and the market for it is intended.

I needed headphones for train journeys to & from London.

These work fine & reduce much of the surrounding noise & constant train announcements.

Using a laptop I needed to cut out any of the computer noises, whisles & bells, so as not to annoy my fellow passengers, so using headphones achieves this.

Phones are adjustable for size, comfortable & stow away neatly in soft pouch supplied.

All together I'm very pleased.

I have not used any other product so cannot make any comparisions.

The Sony MDR - NC40 is a terrific addition to the Sony headphone range. The sound quality is excellent and the NOISE CANCELLING circuitry works extremely well.It is aimed squarely at the travelling public, but is very useful for home use.
The headphones of are of lightweight over-the-head construction, fold-up for storage and are supplied with a neat zipper
carry case. The foam ear pads have a leather type covering which sit comfortably ON-EAR and give an effective seal without
covering the whole ear and making it too hot. This is a great alternative for those who find the ever-popular Ear Buds too
intrusive and uncomfortable for the inner ear canal.
The key feature is the NOISE CANCELLING system which is superb, though some may find it takes a bit of getting used to.
Between the headphones and its gold plated jack plug there is an In-Line Battery case (with attached clip) which takes a single AAA cell.This also has the small Noise Cancelling ON/OFF switch and a tiny red light On indicator. Battery life is
good, though you do need to remember to turn off when not in use. There are NO Volme or Bass/Treble controls on this unit.
It is of reasonably sturdy construction considering its light weight and type of useage.
In use with a SONY X-Series MP3 player these NC40 headphones give excellent sound quality and insulation and although this MP3 player has has its own NC circuitry it's qhite difficult to tell the difference between the two.
To summarise this is an excellent pair of lightweight headphones and if considered a little expensive it's worth bearing in mind that you get what you pay for. Norman B.