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Quieting Down: Noise-Reduction Headphones (3/2008)
by Douglas Dixon
It's a noisy world out there -- with background white noise like computer fans and air conditioning in the home or office or bookstore, and ongoing environmental noise like on a train or airplane. Not to mention the hum and clatter of all those noisy people around you. Whether you're trying to get some work done. listen to music, or just need some rest, it would be nice to be able to withdraw into a quieter place and block out the background noise.
You can start fighting the background sounds with passive noise isolation -- covering over your ears with headphones or plugging up your ears with earphones to keep at least some of the noise at bay.
But to really fight the noise, you need active noise cancellation -- digital signal processing in the headphones that uses a microphone to listen to the outside sound and generate an inverse signal to cancel it. While this kind of processing can't totally eliminate the environmental noise, it can move you away, into a quieter place.
There are lots of these kinds of noise-reduction headphones available these days, from very high end (and high price) to nice sets from familiar names like JVC, Maxell, Panasonic, and Sony for around $50 to $150. See below for some sample products, and my Audio Accessories Gallery for more examples.
Some issues to consider with noise-reduction headphones include noise reduction performance, style and comfort, and portability.
Unfortunately, comparing noise reduction performance is a bit tricky, since the products are not measured with a common testing process, and technical details like the amount of reduction (measured in decibels) are not available. Some manufactures talk of the reduction in percentages: 85% or even 95% reduction, although this rough measure is best for comparing products within that company's line.
Style and comfort issues have to do with your personal preferences for the design of the headset: how it fits on the head, and the size and padding of the ear cup over the ear (or the earpieces for earphones).
And style also relates to portability -- if the headphones are too big and bulky then they will not be convenient to take along when travelling (especially for cramming into carry-on luggage for a phone trip). Therefore some of these headsets have earpieces that rotate to flatten them for storage.
So what can these kinds of devices do for you? Well, you can use these headphones for stand-alone noise reduction, without connecting them to a music player (and you can also use them to listen to music even without batteries). For example, just sitting in a bookstore cafe, for example, you may not consciously notice all the background noise from the equipment and people, but putting on noise-cancelling headphones can make an amazing difference, relieving you from the continuous assault.
It these is music playing around you, like in a restaurant, it sounds further away and clipped, and some parts even can be cut out. Or on the train, the ambient train noise can be cut down -- you'll still hear some of it, but further away (although this may mean you hear nearby conversations more clearly).
And all this is just from using the noise-cancelling feature, without actually listening to music.
When you plug in to a media player and start listening to music, the background noise cuts further away. For example, you may not even hear a phone ring, depending on the frequencies of the ring tone.
Clearly, you should try some of these products out to see how well they work with your kinds of environments and your trade-offs for comfort and portability. As you prepare for your next long trip, you can decide whether the incremental benefits of active noise cancellation are worth the logistical hassle of carrying extra headphones or earphones, or whether you can survive with the passive isolation from plugging your ears and listening to music.
The Maxell line of noise cancellation headphones includes light-weight headphones and new noise reduction earbuds, ranging from around $49 to $129 list (www.maxell-usa.com/index.aspx?id=63;66;521;0).
The Maxell NC-IV Headphones are the current top of the Maxell line ($129 list, $70 street, www.maxell-usa.com/index.aspx?id=63;66;521;0&a=info&pid=335).
Besides the advanced noise reduction, they feature full-size ear cups, leather-lined for comfort, that also swivel to pack flat. The earpieces are particularly comfortable since they are large and well-padded, enclosing the entire ear, and resting on the head.
The cord is textured braded nylon to limit tangling, instead of smooth (like those knot-free shoelaces). It also has an in-line attenuator to limit ear-damaging volumes with low, medium, and high settings. They weigh around 6.5 ounces.
The detachable headphone cord is 3 feet long, with one end that plugs into the left earphone (it's tapered to fit the round edge of the earphone -- other cables might not reach). There's also a 6 foot extension cord, gold-plated 1/4-inch and airline adapter plugs, and a hard-cover travel case to pack these all in -- plus a mini-case with shoulder strap.
Maxell specs a battery life over 50 hours (with 2 AAA batteries), frequency response of 10 - 22,000 Hz, and sensitivity of 106 dB/mW ± 3 dB.
Find the Maxell NC-IV Noise Canceling Headphones on Amazon.com
The JVC line of line of noise cancellation headphones includes models that fold up (with a retractable cord) as well as an earbud design, promising 75% to 85% noise reduction, for $59 to $199 street (http://av.jvc.com/product.jsp?pathId=101).
The JVC HA-NC250 Headphones are the current top of the JVC line ($199 list, $124 street, http://av.jvc.com/product.jsp?modelId=MODL028174&pathId=101&page=1).
(See previous discussion of the JVC HA-HC250 on my Manifest Tech blog)
These offer up to 85% noise reduction (more than 16.5 dB at 150 Hz)., and the earpiece features a double housing structure with extra sound insulation layer. The ear cups are designed to rest on top of the ear, and therefore are smaller than full-size. They also twist for travel. They weigh around 5.3 ounces with battery.
The detachable headphone cord is 3.94 feet long. The product also includes phono and airplane adapters and a zippered hard case for travel.
JVC specs a battery life over 50 hours (with only one AAA alkaline battery), frequency response of 8 - 24,000 Hz, and sensitivity of 102 dB/1mW (when on).
If size is an important issue for you, these JVC headphones are smaller and around an ounce lighter than the Maxell model (which features full-size earpieces). The JVC's ear cups are significantly smaller (around an inch shorter, and also a bit narrower and thinner). As a result, the headphones pack into a smaller space for travel, compacting an inch or so narrower. Of course, both product lines also include lighter-weight models, although with less noise reduction capability.
(See previous discussion of the foldable JVC HA-NC80 on my Manifest Tech blog)
Find the JVC HA-NC250 Noise Canceling Headphones on Amazon.com
But if these collapsable headphones still are just too big to take on a trip, another option is noise-cancelling earphones -- earbuds with an in-line box of electronics to perform the noise reduction. You get the passive noise isolation of the in-ear buds, plus the additional active noise cancelling from the electronics.
While noise cancelling earphones are clearly smaller than a pair of headphones, they're still clumsy to carry -- requiring an extra cable (earphones to box, plus box to your music player) and the extra box, which is bigger than some tiny MP3 players.
While these don't do as good a job noise cancelling as the headphones, they can help reduce the background drone in a public place or on a train or plane. You also may have strong opinions on the comfort of wearing active headphones vs. earphones -- active cancellation is continuously generating sound waves that may be noticeable or wearying, especially with earbuds held tight in your ears.
For example, the JVC HA-NCX77 Earphones promise 80% noise reduction (more than 14dB at 120Hz) from a box that's around 3 1/4 x 1 1/2 inches and under 2 ounces, for around $79 (http://av.jvc.com/product.jsp?modelId=MODL027872&pathId=101&page=1).
(See previous discussion of the JVC HA-NC77 on my Manifest Tech blog)
The control box includes a power switch (the earphones still work when powered off), in-line volume control, and a monitor switch to cut out the music and listen to the outside sound when you need to hear important announcements.
JVC specs a battery life some 70 hours (with one AAA battery), frequency response of 8 - 24,000 Hz, and sensitivity of 90 dB/1mW (when on).
Find the JVC In-Ear Noise Canceling Headphones on Amazon.com