Have you ever wondered exactly how hearing works? How your hearing aids interact with your ears, and how such tiny pieces of technology can amplify sound? It’s a little bit complicated, but Audicus is here to explain just how the human ear hears, and how it interacts with hearing aids.
How We Hear
The human ear is made up of three main parts—the outer, middle, and inner ear. The part of the ear that’s visible, as well as the ear canal, is the outer ear. The eardrum lies at the end of the ear canal and separates the outer ear from the middle ear. The middle ear is a small cavity that houses three tiny bones known as the auditory ossicles. The auditory ossicles are made up of the malleus (hammer), incus (anvil), and stapes (stirrup). The inner ear is actually two different components: the cochlea, which is involved with hearing, and the vestibular system, which controls balance. The cochlea is a tiny, snail-shaped chamber that is attached to the auditory nerve that leads to the brain, while the vestibular system is made up of many different tubes and sacs. The inner ear is often called the labyrinth.
What happens when we hear a noise? First, a series of vibrations called sound waves pass through each part of our ear. When the vibrations strike the eardrum, the eardrum vibrates in response and sends the vibrations to the auditory ossicles. These three bones amplify the sound and pass them along to the cochlea, which is lined with sensory receptors and filled with fluid. The vibrations cause the fluid to start moving, which in turn moves the sensory receptors. The sensory receptors then send an electric signal to the brain, where it is translated into a sound that we understand. It seems like a complicated and long process, but as we know, this all happens instantly as soon as sound waves are created!
Hearing Aids + the Human Ear
Maybe you’re wondering how hearing aids fit into all of this. The short answer is that hearing aids amplify sounds and direct them into the ear. While there are several different types of hearing aids suited for various degrees of hearing loss, all hearing aids have the same main components: a microphone, an amplifier, and a receiver/speaker.
Most hearing loss is due to damage to the sensory receptor cells in the ear, so hearing aids magnify sound waves so the remaining sensory receptors are able to recognize them. The microphone detects sound waves and converts them into electrical signals. It then passes on the signals to the amplifier, which increases the power of the signals and sends them to the receiver. The receiver transmits the amplified signals to the auditory nerve and brain.
The human ear is a complicated and delicate instrument, and it is truly fascinating to discover how it works. If you’re still curious about the different types of hearing aids and how they function, check out our post on hearing aid FAQs.
By: Elena McPhillips