Awareness of Surroundings

Because of their ability to inform us about our environment at a distance, hearing and vision form a valuable pair. Furthermore, they are in many ways complementary. Vision gives you information only about what lies in the direction in which you are looking, while hearing gives you information about your surroundings from all directions. You hear sounds from in front of you, behind you, from the left and the right, and even from above and below you. Not only do you hear sounds from all around you, you can usually tell from what direction the sounds are coming, even without turning your head. To get visual information from all around, you must look around, turn your head and change your focus from side to side, from up to down, and even turn around to look behind you (or use a rear-view mirror).

With hearing, you can remain still, not moving, and yet be aware of activity all around you. With vision, you must move in order to get information about objects around you, but those objects can be static. You can see a book where it is resting quietly on the shelf. But for you to hear that book, the book needs to move. A gust of wind can blow it open and rustle its pages. Or a heavy truck passing on the street may jiggle the shelf until the book falls to the floor with a thud. The rustling and the thud you can detect even if it happens behind you, out of your sight. Vision can give you information about unmoving objects all around you, but to get that information, you must move. Through hearing you can get without moving information from all around you, but the sounds you hear are produced only when something moves.

Unlike vision, hearing is an always-on sense. You can shut your eyes and close off all visual information. You do this when you fall asleep. However, you cannot close your ears. You are always hearing sounds from all around you, even when you are not paying attention to them. And this is good, especially when you fall asleep. It would not be safe or good to completely shut yourself off from your surroundings. Sometimes you need to be awakened, perhaps to be alerted to a danger, as by a fire alarm, or to be alerted that it’s time for work, as by an alarm clock. Because your hearing is always on, that alert is most effectively a sound.

Hearing and vision are complementary in more ways than just providing distinct information about the surroundings. They also affect each other. What one sees can significantly affect what one hears, especially in discerning speech. Similarly, what one hears can affect what one sees, such as in discerning the direction in which a noisy object is moving. Our perception of the world around us is constructed from information derived from all of our senses; none works by itself.