Aliph's Jawbone has garnered a lot of praise - and hype - as one of the best mono Bluetooth earpieces out there. Most of the fuss has to do with Jawbone's "military grade" noise canceling technology. Aliph's Noise Shield Technology is based on technology that was, in fact, developed by DARPA (a military research group) and basically uses some sophisticated software to separate speech from background noise and eliminate the latter from what gets transmitted from your end of the call.
The technology worked quite well in my tests. Note that Noise Shield is a one way street - its designed to make you sound better to the person listening to you, and not the other way around. That makes sense given the nature of hands-free mobile calling (the person talking into the Bluetooth set is likely to be in a noisy environment, like on a city sidewalk, in a moving car, or, um, in a bowling alley), but it's worth clarifying nonetheless. During my testing I used Jawbone in a number of noisy and quiet environs and it did a noticeably good job of eliminating background noise wherever I was.
On the flip side, callers came through to my ear as loudly and clearly as they have with other premium Bluetooth headsets. Jawbone's noise detection software adjusts the volume of its speaker according to background noise, which is a nice feature that's somewhat offset by volume control that's limited to five settings. A premium audio device should offer more than five steps from softest to loudest if you ask me. Jawbone's volume control is also a single button setup that goes from softest to soft to louder to even louder to loudest and then back to softest again. That's the long way of saying there's no way to turn the volume down except to cycle through all five settings. That's also annoying.
Jawbone isn't the smallest of Bluetooth earpieces, and in fact is more than twice as big as some of Nokia and Samsung's more discreet offerings. I found Jawbone to be reasonably comfortable to wear, but a major pain to actually fit onto my ear. Though Aliph includes six ear buds and four ear loops in the packaging, the loops are made from stiff plastic that wants to break when you try to bend it to slip over your ear. Jawbone can be worn without the loop, but then it's just an earbud pushed into your ear that's holding the thing in place ? a smaller earpiece would be much better suited to this sort of usage, but Jawbone's size made it feel like it was going to fall off of my head at any moment.
Also, while Aliph went to lengths to make Jawbone look cool, they did so at the cost of ergonomics. The earpiece's two buttons are kind of hard to reach, particularly the "Shield" button, which is used for powering on/off and answering and hanging up on calls. Once you find the button, you'll also find that it's very small and rather hard to push. But, hey, I guess Jawbone looks kind of cool. For a Bluetooth earpiece, anyway.
All in all Jawbone provides arguably the clearest sound you'll find on any Bluetooth earpiece currently on the market. But it does so at the expense of size and fit. Try to get a Jawbone in your hands - and ear - before you make your purchase. If you're not bothered by the fit, you'll likely love the sound of a Jawbone.