Recent Study Examines How Some Blind People Use Echolocation Similar to Bats


A study published August 31st to the Public Library of Science (PLOS) examined the "mouth-clicks" used by blind human beings that are capable of using echolocation similar to bats to navigate around and even identify objects.

Researchers involved collected  "a large database of click emissions with three blind people expertly trained in echolocation," which allowed them to analyze the transmissions used in human biosonar.  The study focused on the "spatial distribution (i.e. beam pattern) of human expert echolocation transmissions," and showed that "directionality of clicks exceeded directionality of speech," meaning that the clicks were more accurate in indicating the relative locations and descriptions of objects than would be human speech.

While human echolocation is similar to that used by bats, it does differ in that the sound used is in the audible spectrum.  The research done for the study also raised the question of whether or not humans are capable of modifying their mouth-clicks to apply to specific situations, although the answer remained outside of the study's scope.  The researchers did note that "the anatomy of the human head, mouth and lips poses severe limitations on the flexibility of the width of the spatial distribution of a click," but "on the other hand, the direction into which a click is pointed can be varied easily by head-rotation," so it remains to be seen exactly how adaptable human biosonar is.

The study's authors hope to use this data to create a synthetic model of the process to provide for further study.  

Tobias Wayland