HOW DO WE JUDGE THE DIRECTION OF SOUND?

We can judge the direction of sound only because we have two ears. The sound  waves reach the right and the left ear with a small time difference because the ears are at slightly different distances from the source of the sound. The eardrums vibrate, and the ear ossicle transmits the impulse to the inner ear. The inner ear sends it further to the brain where the signals from both ears reach at marginally different times. The brain calculates the direction of the sound from the tiny difference in these times.

WHY IS THE SENSE OF TOUCH IMPORTANT?

Without the sense of touch we would be quite helpless. We would not be able to feel oneself, we would not feel our feet hitting the floor while walking and injuries would go unnoticed because no pain would be felt. We would also be deprived of many pleasant experiences important for social interaction. For blind people the sense of touch is very important. They move around safely be feeling and touching objects in their surroundings. Blind people compensate for their lack of sight by highly developed sense of touch.