How does hearing work?
Understanding your hearing
Structure and mechanics of the ear
In order to understand how to best approach hearing care, it’s important to have a basic grasp of how this special sense of hearing works. When you can better identify the source of hearing loss, you can better know how to treat it. In general, sounds in the world must be transmitted from the environment and converted into nerve signals in our brains for us to understand them. This happens through our external, middle, and inner ears. Keep reading below to learn how these structures work together to produce the experience of hearing.
The outer part of the ear is the largest part of the hearing pathway. This is simply the part of the ear that we can see, and includes the ear canal leading to the middle ear. The external ear captures and focuses sounds into the middle ear, like satellite dish concentrating sound waves into the ear canal.
Sounds from the external ear travel through the ear canal and cause the eardrum to vibrate. The eardrum is impermeable and vibrates according to the different frequencies of sounds. The other side of the eardrum is connected to the three smallest bones in the body. These bones connect with each other and conduct sound vibrations from the middle ear to the inner ear, otherwise known as the cochlea, by vibrating on a membrane of the middle ear called the oval window.
The cochlea, or inner ear, is a spiral-shaped organ filled with fluid. This fluid carries sound vibrations from the external and middle ears to the tens of thousands of tiny hair cells lining the inside walls of the cochlea. These fine hairs are specialized nerve cells that transform vibrations into electrical nerve signals, which are then processed in the auditory center of the brain.
The fluid in the cochlea transmits all vibrations over the base of the cochlea, and stimulates the hair cells to vibrate and send nerve signals to the brain. The hair cells in the cochlea are arranged so that the ones transmitting higher frequencies are closer to the mouth of the cochlea. These high frequency hair cells are like the area of carpet at the front door of a house – since there is more traffic here, these hairs will receive wear and tear faster than other parts of the inner ear.
Once a hair cell deteriorates, it does not regenerate. This means that any damage to the inner ear is permanent. The good news is that most cases of hearing loss can be treated with the right hearing aids.See the Vibe hearing aid family
How hearing affects your health
Your hearing is one of the essential senses through which you receive the outside world. It is a very fine and complex system that is connected to your overall health and well-being. Hearing is not only alerts you to what’s happening your environment – like the changing background sounds that provide constant information about what is around us, or sudden sounds like an oncoming car, or fire alarm, but also allows us to access to one of the most important forms of communication: speech. Our hearing also lets us experience the sounds that please us – like music, or the diverse and calming sounds of nature.The importance of protecting your hearing
How is hearing measured?
Every sound that your ear picks up is made of many pitches and intensities. Pitch (or frequency) is measured in Hertz (Hz) and intensity (or volume) is measured in decibels (dB). Bass sounds like the rumble of a deep voice have low pitch, while treble sounds like children’s voices have high pitch. The healthy human ear can capture sounds from 250 to 8000 Hz. It is normal that very high or very low frequencies within this range need to have higher intensity to be heard by the human ear.
An audiogram shows the range of absolute frequencies (Hz) that can be heard with normal hearing, and the intensity the sound (dB HL) must carry for the ear to pick it up, relative to normal hearing. So when someone has an audiogram that shows they can hear 2000Hz at -10dB, it simply means that they can hear this frequency at a lower intensity compared to the average person. Normal hearing falls between -10dB and 15dB.
The sound of your own voice
Have you ever noticed that your voice sounds different when it’s played back to on a recording? This is because the source of your voice is inside your head, and some frequencies and intensities are reduced when they are absorbed by your skull before they reach the inner ear. This means that the voice you hear tends to have more rich bass tones than the voice that is projected to the outside world. The voice that others hear can sound more tinny and unfamiliar to you, but rest assured that everyone else is used to this voice – it is just you who is not!
Because of the own voice phenomenon, it is a common experience when people first start using hearing aids is that they are not used to hearing the sound of their own voice through the hearing aids, which amplify the sound of the own voice as if it were coming from both inside and outside the body. This unfamiliarity simply requires some time to get used to but usually becomes much less noticeable within a few days of wearing hearing aids.
The emotional world of hearing
The problems of hearing are deeper and more complex, if not more important, than those of vision. Deafness is a much worse misfortune. For it means the loss of the most vital stimulus–the sound of the voice that brings language, sets thoughts astir and keeps us in the intellectual company of people. – Helen KellerSee the Vibe hearing aid family