Motorola has unveiled the Endeavor HX1, a Bluetooth headset which uses a combination of CrystalTalk noise cancellation technology and bone conduction technology dubbed ‘stealth mode’, enabling users to hear and be heard in noisy environments such as concerts or driving in a convertible. The company claims it is the only Bluetooth headset to use true bone conduction technology, a broadside that is surely aimed at competitor Jawbone whose headsets use a sensor that sits against the outside of the face as opposed to the in-ear setup of the HX-1.

The Endeavor's bone conduction stealth mode is started with a touch of a button, activating an ear sensor that seals off outside noise (rather than relying on an exposed exterior microphone). The sensor translates vocal vibrations, "seamlessly converting them to speech." Motorola says the Endeavor has been created with the same bone conduction technology used by special military forces around the world.

The CrystalTalk technology uses sound enhancement algorithms embedded within a Digital Signal Processor (DSP) to enhance clarity and quality and remove background noise. The technology also makes automatic adjustments based on ambient noise.

Bone conduction technology has been around for a while, from early NTT DoCoMo and Vonia headsets to waterproof MP3 players and hearing aids. The technology is safer than traditional air conduction headsets as it bypasses the eardrum, but based on our experience there's a definite (and not unexpected) sacrifice in sound quality.

The Endeavor offers up to seven hours of talk time as well as Motorola's Multipoint technology which enables it to connect to multiple devices. It will go on sale in Asia in July 2009 with other regions to follow although schedule and pricing are not yet available.