The team then recorded the students making three different noises: a 'ch' noise made with the tongue, a 'ch' made with the lips, and the palate click.
After studying the shape of the sound wave that each noise produced, Martínez and his colleagues found that the palate click gives the most detailed feedback about a person's surroundings.
Visual Bias
In animals that echolocate, the skill is often key to survival, and the animals have specially adapted organs for the task, Martínez noted.
Dolphins, for example, have special structures in their noses that can produce 200 clicks a second. Humans can manage just three or four clicks a second.
"It seems reasonably tough, perhaps tougher for those who can see, because we are very visual animals and don't tend to use that ability at all, so there is a 'visual bias' to overcome," said Peter Scheifele, a bioacoustician at the University of Connecticut who wasn't involved in the study.
The average person can develop good echolocation skills in about a month if he or she trains for one to two hours a day. Blind people are likely to pick up the skill more quickly, Martínez said.
In addition to aiding the blind, echolocation could help rescue teams locate people in foggy conditions or help firefighters quickly find exit points in smoky buildings.
The researchers add that artificial echolocation devices, such as wristbands that beep, can't yet outperform the simple tongue click.
"Such devices are worse than natural echolocation at present, because they don't reproduce the complete haptic [touch] perception of the echoes," Martínez said.
|
SOURCES AND RELATED WEB SITES
|
