Around the world with computing system

London: Finding your way around a city you've never visited before can be challenging for a sighted person, let alone the blind.

But help may soon be at hand for the visually impaired as scientists at Georgia Institute of Technology in Atlanta are developing a wearable computing system.

This system can help visually impaired people and firefighters find their way out using auditory signals via bone-conduction headphones.

The prototype system created by Bruce Walker and his colleague Frank Dellaert has been named System for Wearable Audio Navigation (SWAN).

The system guides users with beeps that appear to come from whatever direction the person needs to head in. "We have the user simply walk towards the sound," Newscientist quoted Bruce Walker as saying.

To calculate the user's position and the direction they are facing, the device uses a processor in a backpack to combine Global Positioning System (GPS) location readings with data from cameras and motion and tilt sensors attached to a headband or helmet.

This information is fed into a virtual 3D model of the streetscape or building the person is navigating to calculate which direction the person should walk towards to reach their destination, according to the designers. The device can then generate a series of beeps to guide them.

To make the beeps appear to come from a particular direction, the system varies the timing and intensity of the vibrations transmitted to each earpiece, they said.

The "earpieces" are placed under each ear lobe and they vibrate the skull directly to transmit sounds straight to the inner ear, bypassing the outer ear entirely.

The scientists said that this has advantages over existing systems to help blind people navigate, which tend to use speech to impart directions.

The designers plan to recruit volunteers to test their system later this year.

They also plan to incorporate new navigation aids to help people indoors or near high-rise buildings where they may lack GPS signals.