Human echolocation

How it works

Sound bounces off objects. A sharp click of the tongue makes a sound that returns as an echo¹. The delay tells you distance. The difference between the two ears tells you direction. The tone tells you something about size and texture. A wall sounds different from a tree, and a tree sounds different from a parked car¹.

Every brain does some of this already. Blind people who use it on purpose become very precise. Expert clickers can tell the size, shape and solidity of objects from their echoes¹.

In 2011, researchers in Canada scanned two blind echolocation experts. When they listened to recordings of their own clicks and echoes, their primary visual cortex became active. Sighted controls showed no such activity⁵. The brain region built for sight was processing sound.

The skill can be learned, and age and sight do not seem to limit it. In a 2021 study, blind and sighted volunteers aged 21 to 79 trained over 20 sessions across ten weeks. Both groups improved on every measure⁴. Three months later, every blind participant reported better mobility, and 83% reported better independence and wellbeing⁴.

How common it is

There are no statistics on how many blind people echolocate. A 2013 paper says exactly that, then adds that older reports suggest perhaps 20% to 30% of totally blind people may do it³. Those reports date from 1909 to 1930, so treat the range as a guess rather than a measurement³. Nobody has estimated a share of the whole population. Teaching counts are firmer. Daniel Kish’s organisation has taught his clicking method to more than 500 blind children². A modern survey of blind adults would settle the question.

Try it

1. Sit in a quiet room with your eyes closed.
2. Hold a large plate or a hardback book about 30 cm in front of your face.
3. Make a steady “shhh” sound, or repeated tongue clicks.
4. Slowly move the plate towards and away from your face. Listen for the sound becoming brighter and fuller as the plate gets closer.
5. Have someone else move the plate while you say when it is close.

Is it a problem?

No. Echolocation is a learned skill, not a sign of anything wrong. Tongue clicking is a deliberate technique, and training with it can improve mobility⁴. Mention it to a doctor only if the clicking happens involuntarily, without the person meaning to use it for navigation.

History and culture

Daniel Kish, an American born in 1966, lost both eyes to an eye cancer before he was 13 months old². He learned to click with his tongue as a child¹. He leads blind teenagers on hikes and mountain-bike rides¹. He teaches his method, which he calls FlashSonar, through his organisation World Access for the Blind¹².