But when the lights are out and where vision can't reach, hearing is a very good backup. Thing is, we mostly don't have the need to really listen, so that sense isn't used to its full potential. When there is need , we can utilize it and it takes practice as shown with those who can't see. Sure vision works a lot better, but when combined with more advanced listening, people such as cyclists could benefit greatly from it and it's not about who has a bigger ear drum, tho' it could play a role. It's about how much you contemplate the sound, or think about what you hear.

An easy way to try this out is to slowly move your hand with fingers together from the front of your face to the back side of your head while you make that tongue clicking sound. Make the hand face your head and start out from about 4 inches from your head. When the hand is closest to your ear, notice how the sound changes.