Philips SHN7500 Noise Canceling Headphones are a peculiar product. They happen to be one of those unusual pieces of gear that, depending on how you look at it, has a very smart--or kind of silly--design.
The basic premise behind the headphones, which carry an MSRP of $100, is that you wear them around your neck: a pendant module dangles from the front of the thick, comfortable lanyard, while the soft, silicon earbuds emerge from the portion at the base of the neck. The dongle--it looks a little like a miniature digital voice recorder--houses the noise-canceling circuitry and the unit's single AAA battery. It has a power switch to activate/deactivate the noise cancellation on its front, as well as a convenient volume control slider on its side.
In the package you'll find a separate headphone cord--you plug one end into the minijack on the bottom of the dongle and the other into the headphone jack of whatever device you're listening to (you also get a two-pronged adapter for airline use). If we had a small gripe, it was that the cord could have been at least a foot shorter--though plenty of DIY and commercial workarounds for that are available.
So why is this a smart design? Well, if you're on a plane or train and need to get up to, say, go to the bathroom, all you have to do is disconnect the cord from the dongle, leave your audio player/DVD player/laptop in the seat (or, if you're watching a movie on the in-flight system, you simply leave the cord connected to the armrest jack), and walk away. The lanyard/headphones essentially become a wearable necklace. There have been other headphone systems like this--particularly for use with cell phones that double as music players--but Philips has done a nice job designing this model to be fairly unobtrusive. The contraption isn't too bothersome to wear and with the earbuds sitting there, dangling on your chest, they're always within easy reach. They also feel pretty comfortable in your ears. You get three sizes of replaceable rubber sleeves or buds to choose from, and one should allow you to get a tight seal.
Of course, the flip side to the whole thing is that you do have a dongle hanging from your neck. And unless you're getting up from your seat a lot on planes, trains, or even in your cubicle, there's some question whether you need to be weighed down in any way by a dongle, especially when the noise cancellation circuitry isn't terribly effective. By that we mean that we barely noticed a difference when we flipped the switch on the dongle to activate the noise cancellation.
Those who don't like the pressurized feeling of more intense noise cancellation might find this subtle approach refreshing, but we thought Philips could have kicked it up a notch. The fact is, a good tight seal with a pair of earbuds should "passively" block out a lot of sound. While the seal we got with the Philips SHN7500 Noise Canceling Headphones wasn't as tight as the seal we've gotten with some other 'buds, including our Shure E4c reference 'buds, we did manage to cut down significantly on the noise level as soon as we jammed these guys in our ears. With that base level of passive noise reduction set, you then expect to achieve almost complete silence when you engage the noise cancellation. Instead, we ended up having to listen very closely to hear the difference between passive and active modes.
On a more positive note, the Philips SHN7500 Noise Canceling Headphones do sound pretty good. They're short on bass compared to most other $100 earbud-style headphones, but they offered decent clarity and didn't distort at higher volumes. In many ways, their sound resembles that of the Sony MDR-EX71SLs, but those can be had for around $30 online.
Another nice feature of the Philips is that the headphones will work whether or not you have the power on. So unlike many noise-canceling 'phones that simply go dead, the SHN7500s will continue to work (albeit without the noise cancellation) even if the battery dies in the middle of a flight.
Conclusions: Philips definitely made these with the traveler in mind, though they're perfectly suitable for work use, particularly if you're confined to an "exposed" cubicle, where you find yourself pulling your headphones on and off as visitors stop in. The SHN7500's wearable design offers a lot of convenience for frequent flyers, especially if you're someone who gets up a lot during flights. These headphones are also smaller, lighter, and much less expensive than the Bose Quiet Comfort line of headphones. All that said, their noise cancellation is lackluster, so it's hard to recommend buying them unless you love the design or find them significantly discounted.