The Jawbone comes out of the box with a medium sized ear-hook and earbud, but these can be changed for smaller or larger items, all of which are supplied. I found the medium sizes to be perfect, and was pleasantly surprised at how comfortable the Jawbone is. Not only is this the most comfortable Bluetooth headset I've ever used, but it's also extremely easy to put on, even using one hand. The leather ear hook slips easily over your ear, then the earbud sits comfortably in your ear, while the device itself rests upon your face.
It's the way this headset rests against your face that gives it its name. On the inside of the device is a sensor that reports movement from your jawbone, which indicates that you're talking. The Voice Activity Sensor (VAS) detects when you're talking, then sets the Noise Assassin algorithms to work on separating the frequency of your voice from the ambient noise. It's the Jawbone's ability to tell exactly when someone is speaking, that allows its noise suppression algorithms to work so effectively - without that VAS, it would be difficult to tell exactly what is the user's voice and what is background noise.
Of course all those clever sensors and complex algorithms wouldn't mean a thing if the end result isn't up to scratch, but thankfully that's not the case. In fact, the noise suppression in the Jawbone is so good, that when I called my wife from my car, while travelling at speed on the motorway, she didn't even realise that I was driving! When it comes to eliminating ambient noise, the Jawbone is a master - it definitely lives up to that Noise Assassin moniker.
The Jawbone also ships with an excellent USB charger. I say excellent, because like a Blackberry charger that I got my paws on years ago, this charger has a USB port on it, so you can plug any USB charge cable into it. Obviously the Jawbone comes with its own USB charge cable, but if you wanted to charge, say, your iPod or your Windows Mobile Smartphone, you could simply plug their cables into the Jawbone charger and start juicing up. I'm not sure whether this is the reason that Aliph has included this kind of charger, but it's very welcome nonetheless. On the downside, the Jawbone uses a proprietary charge connector, rather than the nearly ubiquitous mini-USB.