Have you ever considered the marvel of hearing? Our ears are a complex set of structures and cells that work with our brains to allow us to hear an incredible range of sounds. Researchers have discovered that our ears are as ancient as they are amazing, and have served some very important functions throughout human development. Some parts of the ear even date back to prehistoric times, and can be found in our aquatic ancestors.
The History of Your Hearing System
Dr. Kathleen Cullen at McGill University in Montreal has been looking at the origin of the hearing system, and has made some fascinating discoveries. She found that there is not one but two sensory systems within our ears, and one is much older than humanity itself. Interestingly, these systems aren’t directly involved with hearing, but with something more fundamental.
It all starts with the vestibular system. Located in our ears, this is the system that deals with balance, makes sure we know which way is up, and keeps us from falling over. The vestibular system gages the height, depth, and width of the space around us, as well as keeping track of the movements and position of the body to help us with coordinated activities.
Using Our Ears to See
One of the most important functions of the vestibular system is to allow us to see clearly when we’re moving. If this system wasn’t functioning properly we’d see everything as a blur, and only be able to focus when standing still. “If we didn’t have a vestibular system our eyes would bounce around like a GoPro, like you put a GoPro on your head,” explains Cullen. The vestibular system notices how we move, and tells our eyes and head how to adjust to keep our gaze steady. With the vestibular system up and running, our eyes are able to compensate for our movements, keeping our vision clear.
Where It All Began
So, what about the two systems Dr. Cullen is researching? The older of the two vestibular systems is around 300 million years old, and is among the oldest systems found in living organisms. This system allows organisms to maintain balance and spatial awareness in a smooth environment, such as water, and deals with slower movements. We still use the older system for some movements, like shaking our heads, since this system is more precise for slower, sweeping movements.
Unlike the older, slower system, the new vestibular system was developed much more recently, around the time organisms began moving out of the water and onto the land. On land, we need to make quicker movements, and require a more complex system that can react faster to changes in the environment, and keep us from losing our balance no matter what comes our way. It allows us to make sudden, sharp changes in movement, without losing balance or focus.
The Hearing Function
Ears aren’t just about balance, they also allow you to hear! The structure of the ear can also be traced back to our marine ancestors. The middle ear is home to three tiny bones, known as the ossicles, that help us to hear by vibrating against the ear drum. While it’s true that fish don’t have ears, these bone arrangements in human ears closely resemble the jaw bones of some fish, such as the zebrafish. It seems that land animals developed hearing in a process called exaptation, where some features acquire functions they weren’t originally used for.
Why Study Origins?
Dr. Cullen’s research is giving us a whole new understanding of the human ear, and the more we know about the history of the ear and the hearing system, the more we’re able to expand our knowledge of the hearing system to find new ways to treat hearing loss.
Are you experiencing hearing loss, or problems with balance? Whether it’s a problem with the cells in the inner ear, the ossicles, or the neural pathway to the brain, we’re here to help. At Hearing Health, our top priority is your hearing health, and we want to make sure you’re hearing clearly. Make an appointment for a hearing assessment, and together we’ll discover your level of hearing loss and the best treatment to get you back to hearing. We have a wide selection of hearing aids from the world’s leading manufacturers, and will work with you to find the perfect device that fits seamlessly into your life.