A built-in proximity sensor tells the headset when it has been placed in the user's ear. Calls are automatically sent to the headset when it's wrapped around the ear, but the moment it's removed calls divert to the phone's speaker.
Music playback follows the same principle, pausing tunes automatically when the headset is removed.
Paired with an iPhone 4, I found the headset worked flawlessly. It even adds a second battery indicator to the phone's display, tracking headset battery levels in real time.
The iPhone voice control system, Siri, can also be controlled by the Voyager, although sadly using the headset doesn't increase Siri's accuracy.
Clear, spoken announcements from the Voyager such as "two hours battery remaining" or "phone connection lost" are a boon to anyone who has struggled with the cryptic patterns of flashing lights and beeps emitted by lesser headsets.
The supplied USB adaptor allows the Voyager to be used with a PC or a Mac. While most features worked as expected this way, I found the automatic music play/pause feature less reliable on a computer.
Battery life is impressive, providing up to six hours of talk time on one charge, but in my testing I found the remaining power dropped quite rapidly if the headset wasn't used regularly. Left idle for a week, the headset lost around 70% of its charge, so it's not the kind of thing you'd want to throw in the glove-box and forget about.
Despite the impressive build quality and clever features on the headset I remain unconvinced. I have no problem with the device per se; instead, my issue is with Bluetooth headsets in general.
For similar money motorists can get a professionally installed car kit that routes calls through the front speakers. Not only is it more comfortable, but it also requires zero charging – and automatically mutes the radio.
Even taxi drivers, formerly one of the core markets forBluetooth headsets, now receive their instructions as text alerts, so the gadgets are surplus to their requirements.
Perhaps I've overthought this, but by a process of elimination the only people who have a genuine need for Bluetooth headsets are unregistered minicab drivers dabbling in nefarious sidelines. And that's not something I'm keen to be mistaken for as I drive along the street.
Plantronics Voyager Pro UC, £139.99
Positives: one of the cleverest Bluetooth headsets available.
Negatives: pricey, conspicuous and far from bonnie.