For several years, Bose's QuietComfort series has been the gold standard of noise-cancelling phones. Recently, a couple of interesting competing models have appeared, both with a feature yet not available from Bose: Bluetooth connectivity.

The first two such phones that we know of are Nokia's BH-905 (which won a Gear of the Year Award from here's how! last year) and Sennheiser's brand-new PXC 310 BT. You can stream music wirelessly to either of these headphones from any music device with Bluetooth AD2P wireless technology, such an iPhone, iPod Touch or BlackBerry Bold. Not only can you dispense with the audio cable between phones and player, you can adjust volume and pause your music with controls on the headphone.

Do these wireless newcomers block out noise as effectively as Bose's wired models? Do they sound as good? Does their wireless operation compromise audio quality? To some degree, that depends on the player's Bluetooth transmitter, but it also depends on the phones' amplifier and Bluetooth receiver.

To find out, I tested them against Bose's latest model, the QuietComfort 15. I wanted to try these phones in an environment with a consistent level of noise, so I listened in my kitchen, standing a foot away from a range hood with both exhaust fans going full blast. I played some favourite music from an iPod Touch, choosing tracks with subtle inner details and nuances of expression that could easily be masked by the noisy fans.

Bose QuietComfort 15

Priced at $400, the QC15 comes with a very nice travel case, a battery, headphone cable, airline adapter and quarter-inch adapter jack.

Bose's headphones are justifiably praised for their comfort, sound and noise isolation. Unlike the Nokia and Sennheiser phones reviewed here, the QC15 covers the entire ear, so they block a fair bit of noise even without the active noise cancellation turned on. The shape and materials of the earcups and headband make these phones very comfortable; the ear cushion material also improves acoustic isolation.

The QC15's newly designed noise-cancelling circuitry employs microphones inside and outside the earcup; this improves the accuracy of noise measurement, Bose says. The QC15 runs on a single AAA battery, which Bose says will provide about 35 hours of use. A green LED below the switch on the right earcup lights up when the QC15 is turned on. Like all Bose QuietComfort headphones, the QC15 has to be turned on to operate. So remember to turn it off when you're finished listening.

By a small margin, the QC15 seemed to provide the best noise of these three headphones. The sound was excellent: pleasantly smooth with full, deep bass. Very occasionally, bass seemed over-prominent, but only in recordings that themselves emphasize bass, for example Leonard Cohen performing "Ain't No Cure For Love" in the London concert. But most of the time, I was impressed by the great bass definition and extension, for example in the accompaniment to Norah Jones singing "Turn Me On" on Come Away with Me. Instruments and vocals, both male and female, generally sounded very accurate.

Nokia BH-905

If you're raising an eyebrow at the inclusion of a leading cell-phone brand in an article about high-fidelity headphones, you can stop right now, because this is an excellent product. Priced at $350, the BH-905 comes with a leather case, headphone cable, various adapters, and a charger.

Nokia says the built-in rechargeable battery will provide 16 hours of music playback time with Bluetooth and noise cancellation turned on, 24 hours with Bluetooth on and noise cancellation off, or 40 hours with a wired connection and noise cancellation. If you use the BH-905 with a wired connection and noise cancellation turned off, there's no drain on the battery at all. This is the only headphone of the three reviewed here that you can use with a dead battery.

It's unique in another respect as well. It has speech microphones, so that it can be used for hands-free calling, making it the ultimate accessory for an iPhone, or other Bluetooth music phone.

This NH-905 sits on top of the ear, rather than covering it entirely. That may make it a touch less confining than the Bose QC15, but it also means that there's less acoustic isolation. The BH-905 has a total of 10 microphones: eight for noise cancellation and two for speech.

You turn on noise reduction with a small switch on the bottom of the left earcup. I thought the NH-905 provided the least noise cancellation of these phones, by a small margin. But it's certainly very effective.

For wireless operation, you have to pair the BH-905 with your Bluetooth-equipped smartphone or music player. To do this, you turn on Bluetooth on your player, then press the master switch on the BH-905's right earcup until the LED at the bottom flashes blue. After a minute or so, your player will ask if you want to pair with the headphone. Thenceforth, the BH-905 will automatically connect to the player wirelessly whenever you turn it on.

I didn't notice a significant difference in sound quality between a wired and Bluetooth connection to my iPod Touch when using the BH-905. I was very impressed with its sound quality. The BH-905 has lovely detail and sparkle, though on recordings with lots of high-frequency energy, the sound can occasionally become a little tizzly. Vocal and instrumental timbres almost always sounded wonderfully natural. On a rollicking concert of jazz standards recorded in Baden, Switzerland in 1969, Albert Nicholas' clarinet sounded completely convincing throughout its range; so did the Henri Chaix's piano and Romano Cavicchiolo's drums.

Sennheiser PXC 310 BT

Priced at $450, this wireless noise-cancelling headphone is a compact folding design, enabling it to fit into a travel pouch that is considerably smaller than the cases that come with the Bose and Nokia phones. If you're trying to fit a lot of stuff into a small carry-on bag, this may be an important consideration.

Besides the pouch, the headphone comes with an audio cable and various adapters, plus a USB charger for filling up the removable rechargeable battery. You can also charge the battery from a PC with a USB cable. According to Sennheiser, the PXC 310 BT will run for eight hours with Bluetooth and NoiseGuard noise-cancellation both turned on, 12 hours with Bluetooth turned on but NoiseGuard turned off, or 20 hours with Bluetooth turned off and NoiseGuard turned on. You can also operate the PXC 310 BT unpowered, with a wired connection and NoiseGuard turned off.

There's a Quick Guide booklet in many different languages, but no printed manual. For a full technical briefing on the PXC 310 BT, you'll have to load the supplied CD into your computer, and read a PDF file in the language of your choice. Doing so will make it easier to figure out the pairing process.

It's not that difficult. Activate Bluetooth on your music player, and it should start looking for compatible devices. Make sure the headphone is turned off, then hold the master switch in the centre of the right earcup until the LEDs surrounding the switch flash blue and red. After a minute or so, your player should discover the Sennheiser headphone and ask if you want to pair with it. Thereafter, phone and player will connect whenever they're turned on and within range - about 10 metres.

The PCX 310 BT sits on top of your ear, and is quite comfortable. It's a tighter fit than the Nokia. With NoiseGuard turned on, I thought the Sennheiser was slightly more effective than the Nokia at shutting out noise, and slightly less effective than the Bose. The differences were very slight however.

I liked the sound a lot. Bass was very satisfying, a little leaner than the Bose, but with superb detail. Occasionally, the sound can become a touch hard, but generally I really appreciated this headphone's superb clarity and precision. It was excellent at revealing inner details, for example the lovely instrumental accompaniment to Jennifer Warnes' cover of Leonard Cohen's "Famous Blue Raincoat." Interestingly, the sound seemed a tad smoother with a Bluetooth connection compared to a direct wired connection to my iPod Touch.

Which One?

The way you plan to use your phones will give you a good idea of which one might be best. I really like the freedom that wireless operation provides. If that's not important to you, then you'll probably be swayed by the lovely warm sound, superb comfort and great noise isolation of the Bose QC15. If portability is key, you'll love the compact design of the Sennheiser PCX 310 BT. If versatility is what you're looking for, you'll appreciate the fact that the Nokia BH-905 can work without battery power, and that it can be used for hands-free calling.

Headphones are a product that you really have to try for yourself, not just to assess their sound quality, but also their overall feel and comfort. But I can't imagine anyone being disappointed with any of these phones' sound quality, or with the effectiveness of their noise-cancelling systems.

Article Tags:  Bose, QuietComfort, QC15, noise, cancelling, canceling, comfort, headphone, iPod, Nokia, BH-905, Bluetooth, wireless, Sennheiser, NoiseGard, PVX 310 BT, iPhone