Understanding How We Hear
Ever wondered how our ears work? Like the rest of our body, these organs are an amazing piece of equipment that allow us to enjoy the sounds of our children’s laughter, the warning signals in our environment and the language of our loved ones.
When you turn your head toward sound, it’s a natural movement. That simple act begins a process of sending noise through a complex system of canals, compartments and nerves until it arrives at the brain to be interpreted as recognizable sound.
It begins in the outer ear, or pinna, which acts as a funnel, collecting the noises in our environment and directing them inward through the ear canal until it reaches the ear drum. Think of the ear drum as a tightly pulled layer of tissue that acts as a seal – much like the membrane of a drum – separating the middle ear from the outer ear and creating a pressurized environment conducive for transferring sound.
Ever play a game of Mouse Trap when you were a kid? If you remember the fun chain of events that little silver ball set in motion, you can envision what happens when sound vibrations hit the ear drum. The vibrations activate three small bones on the other side of the ear drum: the hammer, the anvil and the stapes (or the stirrup, as you may have learned in elementary school) – all of which are connected by small ligaments and are responsible for amplifying sound. Vibrations activate the hammer first, then the anvil and finally the stapes, which thumps against the seal at the other end of the middle ear called the oval window.
Next, the sound vibrations enter the inner ear, a two-chambered compartment, each with its own unique type of fluid. The compartment near the back of the inner ear is our balance center. When our perilymph fluid is level, we feel balanced. If we tip left or right, the fluid touches the tissue in the canal and sends a signal to the brain, giving us the feeling of being off balance.
The second compartment resembles a snail shell and is called the cochlea. There, sound vibrations travel through the endolymph fluid to the organ of Corti, where our sensitive hair cells reside. These cells are the ones responsible for identifying different frequencies in the sound vibrations and translating them into electrical impulses -- much as old telegraph operators used to interpret Morse code. From there, the impulses travel along the auditory nerve to the brain for interpretation into the every day sounds we know and understand.
Like the other organs in our body, our ears benefit from regular exercise, proper diet and protection from excessive noise. By maintaining good health overall, you increase the likelihood you’ll maintain your hearing health, too.