Listen Up

The adaptability and unutilized skills of the human body are amazing.

From New Scientist...

Clicking my tongue quickly and scanning with my head, I move cautiously forward, catching fleeting images of bodies darting hither and thither. I follow spaces that are clear, avoiding clusters of bodies, keeping my distance from bouncing balls. I am not afraid - to me, this is a puzzle. I turn my head and click over my shoulder. I can still hear the wall of the building. As long as I can hear that, I can find my way back.

Humans probably used to rely on echolocation far more in the days before artificial lighting, when we had to find our way round in the dark. The readiness with which people learn sonar suggests to me it may be an inbuilt skill.

The characteristics of an active signal can also be changed to fit the situation. For instance, I click more rapidly when moving fast, and more quietly in quieter environments so as not to get more information than needed. Large objects like buildings can be detected hundreds of yards away. Up close, objects about the size of a credit card can be detected.