Seeing with Sound From: Proto - Winter 2007 - page 29 At dusk, bats navigate through twilight, zeroing in on prey they can't see by using pulses of ultrasound (beyond the range of human hearing) that they generate in their larynx and send out through their nose or mouth. The bats' highly sensitive ears then catch echoes of waves bouncing back from objects in their path, and the bats use the timing and shape of the returning waves to calculate the objects' positions as well as their shape and texture. This remarkable adaptation, which enables bats to detect objects as fine as a human hair, allows them to thrive at night, when there is less competition for insects and other food. Modeling an invention on the bats' echolocation sonar, researchers at the University of Leeds recently introduced a carbon-graphite collapsible walking cane to aid the visually impaired. The UltraCane's handle emits ultrasonic waves that bounce off objects as far as four meters away and send signals to the user through two vibrating buttons on the handle. The strength of the buttons' pulses indicates the direction, height and distance of the objects. The same part of the brain that a bat uses to orient its movements - the superior colliculus - helps a human process the buttons' pulses to build a spatial map in her mind's eye of how the obstacles are arranged, allowing her to walk more quickly and confidently than she could with an ordinary white cane. Links: UltraCane http://www.soundforesight.co.uk/index.html http://www.atkratter.com/mobility/ultracane.htm http://www.sense.org.uk/deafblindness/life/technology/mobility/UltraCane.htm http://www.qac.ac.uk/enterprises/ultracane.html http://www.ic-online.co.uk/it040001.htm Sonar System for the Blind http://www.qinetiq.com/home/technologies/technologies/materials/smart_materials/vibroacoustics/ultracane.html