using sound information
Communication isn't the only thing that hearing allows us to do. It can also provide us with information regarding elements of our surroundings, such as passing cars, blowing wind, and barking dogs.
A person's ability to tell the direction from which a sound comes from (sound localization) depends on binaural hearing which means hearing with both
ears. For example, a sound coming from the right side of a person reaches the
right ear sooner than the left ear. The sound is slightly louder in the right
ear due to this. The brain recognizes this tiny difference in time and
loudness and so it determines which direction it came from.
The doppler effect is related to sound localization in that it allows a person to tell where a sound-producing object is moving. The sound waves of, for example, an oncoming car, are pressed together, resulting in more vibrations reaching the ear in a given amount of time. The differences in the resulting pitch can be used to judge how fast an object is moving, or whether an object is moving at all. A demonstration of the doppler effect can be heard here.
