Talking to yourself is no longer a sure sign of insanity. In fact, on busy city streets all over the globe it is commonplace to see men in suits yapping away to no one in particular. Or teenagers walking side-by-side, talking -- but not to each other. No, we are living in a new age -- the Bluetooth Age.

Smaller and smaller these devices get with each new release -- and with clearer sound and more hands-free features. One brand that long predates the invention of wireless Bluetooth technology, but is synonymous with superior sound performance is Sennheiser.

The German microphone manufacturer has released a new Bluetooth headset designed for the busy business executive that spends more time talking on his phone than talking to his own wife. One particular point of appeal will surely be the unit's talk time: infinite, according to the company. How can that be? Well, Sennheiser wisely allows for interchangable batteries with the BW-900. As one battery expires, simply pop your spare into the unit while the expired one recharges.

But what about the sound? Well, the BW-900 provides the clarity that you would expect fom a Sennheiser. It boasts Sennheiser's "Adaptive Intelligence" digital signal processing technology which detects the background noise environment and boosts signals to accomodate. Perfect for when a conversation starts in the office, moves onto the pedestrian-filled street, and ends in a loud subway station.

Priced around £189.99, the BW-900 is not for everyone's budget. But its three adjustment speaker rings means this attractive over-the-ear headset, weighing in at just 26 grams, will fit comfortably on just about anyone's ear.

So if you're looking for a high-quality Bluetooth ear piece to match your phone and your lifestyle, the Sennheiser BW-900 might be just the accessory you're looking for. Just don't complain if you're mistaken for a crazy person.