A Look Inside Our Ears
Ever wonder how our ears hear? Our amazing ears covert sound waves that are picked up by the outer ear and magically transform them into signals our brains can understand. But, how? Let’s take an imaginary ride inside these incredible things we call ears!
The Outer Ear
First, sound waves are gathered by our outer ears. Sometimes, the outer ear is referred to as the pinna or auricle. The unique shape of the external ear gathers sounds and filter or funnels the sound waves down the external ear canal towards the ear drum. The ear drum or tympanic membrane moves or vibrates as sound waves hit it.
The Middle Ear
Once sound waves hit the ear drum, they enter the middle ear area. The middle ear houses the three smallest bones in the human body. The malleus, incus and stapes. The back side of the ear drum is attached to the malleus. The vibration of the ear drum sets the three small bones in motion. Each bone is attached and articulates with the next. The three bones amplify the sound vibrations as they move through to their next stop, the inner ear.
The Oval Window
Sound energy from the middle ear is taken next to the oval window. The oval window is the first structure of the inner ear. The inner ear, also known as the cochlea, is shaped like a snail shell and is filled with fluid. Inside the cochlea, you find the organ of Corti.
Inner Ear Hair Cells
The sound vibrations are finally transformed into electrical energy by the inner ear hair cells. These microscopic hair cells are grouped by outer and inner hair cells. Both outer and inner hair cells take sound vibrations and convert them to electrical impulses. These electrical impulses will exit the cochlea and travel up the 8th cranial nerve to the brain.
The Brain
Once in the brain, these electrical signals are routed through a complex auditory pathway and processed in the temporal lobe of the brain, thalamus and auditory cortex. These areas decode the electrical impulses and turn them into meaningful speech or sounds. These areas also add texture to the sounds providing key information like directionality and location.
In a nutshell, this is how your ears should hear under normal circumstances. This amazing chain of transformations from outer ear to brain happens day in and day out from infancy to adulthood and beyond. However, anything that derails this transmission of sounds can lead to hearing loss.
If you notice a change in your hearing thresholds or ears, please consult your audiologist. Healthy hearing is for everyone! And Charlotte Speech and Hearing Center is here to help you hear the best you can. For more helpful information, like this, visit our blog, and follow us on Facebook and Instagram.
Blog written by Julie Palazzolo, M.A. CCC-A, Senior Clinical Audiologist at CSHC