Our earbuds allow the blind to be able navigate their surroundings through echolocation.
Bats use echolocation to find their way in the dark since their eyesight isn't very good. They emit a sound that bounces off of objects and rebounds to hit them so they know what their surroundings are.
You press the button on the clicker and sound waves bounce off of your surrounding objects. When the rebounding sound waves hit you, you'll hear it through the earbuds.