Humans Can Develop Bat-Like Echolocation

July 9 -- WEDNESDAY, July 8 (HealthDay News) -- Humans can develop echolocation, a system of acoustic signals used by dolphins and bats to "see" their surroundings, new research has found.

Spanish researchers say that producing certain kinds of tongue clicks helps people to identify objects around them without having to use their eyes, a skill that would be benefit the blind. This ability could also help firefighters, rescue teams or even people lost in fog, according to Juan Antonio Martinez, a researcher at the University of Alcala de Henares in Spain, said in a news release.

"In certain circumstances, we humans could rival bats in our echolocation or biosonar capacity," he claimed.

In their first published study, the researchers analyzed the properties of various sounds and identified what they believe is the most effective sound for human echolocation.

"The almost ideal sound is the 'palate click,' a click made by placing the tip of the tongue on the palate, just behind the teeth, and moving it quickly backwards, although it is often done downwards, which is wrong," Martinez said.

Palate clicks "are very similar to the sounds made by dolphins, although on a different scale, as these animals have specially adapted organs and can produce 200 clicks per second, while we can only produce three or four," he explained.

The study appears in the current issue of the journal Acta Acustica united with Acustica.

A method to teach humans how to emit, receive and interpret echolocation sounds is being developed. The first step is for a person to learn how to make and identify his or her own sounds, which are different for each individual. The next step is to learn how to use the sounds to distinguish between objects according to their geometrical properties.

No special physical skills are needed to develop echolocation, said Martinez, who noted that some blind people have taught themselves the ability through trial-and-error.

"Two hours per day for a couple of weeks are enough to distinguish whether you have an object in front of you, and within another two weeks you can tell the difference between trees and a pavement," he said.

More information

The University of Rhode Island has more about marine mammal echolocation.

SOURCE: Plataforma SINC, news release, June 30, 2009