2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Echolocation for orientation in space is used not only by bats and dolphins. For some people, this method is almost the only means of obtaining information about the world around them. However, the existence of echolocation in humans was confirmed recently, and they began to study it even later. The authors of a new article, published in the journal PLOS Computational Biology, present developments that could form the basis of echolocation simulators.
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Echolocation is a skill that many animals possess. For example, bats and marine mammals make special sounds for orientation in space. People with impaired vision have also adopted this method: with the help of a special click of their tongue, they listen to the echo reflected from the surface of objects and understand the location of objects around. This gives them the ability to avoid obstacles, walk on their own and even ride a bike. Echolocation in humans has been documented, but there is still no data on the features of the sounds themselves.
The authors of the article conducted a study on three adult blind volunteers who have been using echolocation since about the age of 15. Scientists invited them to make the necessary "clicks" in a special room and recorded sounds in order to find out the specifics of the acoustic properties and the trajectory of sound wave propagation.
It turned out that the sounds of echolocation are very different from the sounds of ordinary speech. With the help of a cone fixed near the mouth of a person, the authors found out that the feature of echolocation lies in sound production. So the level of the emitted signal remained almost constant, but going beyond the cone, it fell at a greater speed than for simple speech. The duration of the clicks lasted about three milliseconds, their frequency varied from two and four kilohertz to about ten. The angular resolution achieved by the subjects also had some differences, but more often it was approximately from one to several degrees.
Spectral characteristics of clicks of three subjects
The scientists decided to use the obtained data to create a mathematical model for simulating human echolocation for further testing. Now scientists want to figure out how "magic clicks" help identify various objects. In their opinion, carrying out such tests on humans has its own limitations and peculiarities. Therefore, the authors thought about creating a computer model or a special device, an "artificial mouth", which can simulate human sound production during echolocation. With him, scientists plan to deal in detail with all the intricacies of echolocation without the involvement of people.