How Do We Hear? Anatomy of the Ear

August 2, 2018 • Newsletter, Summer 2018

Our ability to hear is nothing short of a miracle.

If we heard any better, we would hear the movement of the air molecules around us. And although some animals have better hearing for certain pitches, human hearing is most sensitive in the range of 500 to 3000 Hertz (cycles per second), which is precisely the range of the human speaking voice.

ear anatomy

The outer ear

The outer ear, the only part of the ear we actually see, increases our hearing sensitivity by about 10 decibels (dB) and helps us to locate the source of the sound. The ear canal is also part of the outer ear and leads to the eardrum. The eardrum vibrates when sound waves arrive at it and transfers the sound energy to the bones of the middle ear.

The middle ear

The middle ear is an air-filled space containing the three smallest bones in the human body, the hammer, anvil and stirrup.

“If we heard any better, we would hear the air molecules moving around us.”

These tiny bones—all three together fit on a fingernail—direct the vibrations to the fluids of the inner ear.

The inner ear

The inner ear is made up of several fluid-filled canals. The energy waves enter the inner ear and create pressure waves. These waves stimulate nerve cells within the inner ear, which then sends nerve impulses along the auditory nerve to the brain.

The brain

Although it is the outer, middle and inner ear that allow us to detect sounds, it is our brain that allows us to process and understand the meaning of those sounds.

Our brain—using the input from our ears—decodes the complex signals such as speech that are a part of our everyday life. Our amazing ears—and our brains are able to detect and process millions of different sounds, and allow us to communicate with the people around us.

© 2018 Hearing Healthcare News

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