Hearing is an important sense. As such, there are a number of different medical devices that help people with hearing difficulty or deficiencies in the ability to hear sounds. Depending on the specific hearing deficiency, there is a specific device that can help. Some of the most utilized include standard hearing aids, bone conducting hearing aids, and cochlear implants.
Below is a closer comparison of how hearing aids differ from cochlear implants, as well as everything you need to know about them. While you may only need one or the other, understanding the many hearing assistive devices can allow you to have a better understanding of what is available with current technology.
Underlying Mechanism of Hearing
To adequately understand the differences between hearing aids and cochlear implants, it is critical to understand a little bit about the underlying physiology of hearing and how each ear component contributes to the ability to hear sounds.
Below is a closer look at the outer, middle, and inner ear and what each component contributes when it comes to your ability to hear.
The outer ear is composed of the pinna, ear canal, and eardrum. When sound reaches the ear, the outermost structure of the ear, known as the pinna, funnels the sounds into the ear canal. From the ear canal, the sound waves are met with a thin membrane that absorbs the energy by slightly stretching and moving.
While the outer ear may not seem like anything special, the structures of the outer ear play a role in your ability to localize sounds. Without the pinna, for example, it may become harder to identify the source of a sound.
The middle ear can be thought of as the middleman as it simply connects the eardrum to the inner ear. This is accomplished through the use of three small bones that oscillate and move in concert with the eardrum.
In addition to aiding in the conduction of sound through the ear, the middle ear is also responsible for maintaining pressure balance between the outer and middle ear. The eardrum is impermeable.
As a result, a pressure difference from the environment and middle ear can cause pain and even damage if it is unable to equalize. The sensation of your ears popping is actually your middle ears doing their job in establishing pressure equilibrium across the eardrum.
The inner ear is where the kinetic energy from the sound wave is converted into a nerve impulse sent to your brain for interpretation. This is accomplished through the organ known as the cochlea. The cochlea takes the kinetic energy from the middle ear bones and converts it into nerve impulses that can convey tone, pitch, and volume.
The cochlea’s main subunit are hundreds of sensory hairs that are all fine-tuned to a specific frequency of sound. When the middle ear bones strike, the cochlea vibrations are sent throughout its snail-like structure. Then, the corresponding hair is triggered, and an impulse is sent down the auditory nerve to the brain.
As the name implies, cochlear implants are implants that have something to do with the cochlea or inner ear. More specifically, the cochlear implant is essentially a replacement to the cochlea and every other part of the ear.
Below is a more in-depth look at cochlear implants and what makes them unique when compared to hearing aids.
Internal Components of Cochlear Implants
There are two main components to cochlear implants, and this includes the part that is implanted inside of the body and the external unit. Unlike hearing aids, cochlear implants go into the inner ear that must be inserted by a surgeon. Cochlear implant surgery is usually done under general anesthesia.
The internal component of a cochlear implant is a series of electrodes positioned to stimulate signals to be sent down the auditory nerve. Typically, this component consists of a small array of electrodes inserted into the snail-like structure of the cochlea through the oval window.
These electrodes will fire at the approximate location of where the hair for that tone would be located. Essentially this array acts as a way to replace the damaged hair cells of the cochlea.
The other component of the implant includes an antenna that is placed on the surface of the skull. This receiver is the part that communicates with the external unit.
External Components of Cochlear Implants
The external device of the cochlear implant is the brain of the operation. The outer unit contains a microphone and transmitter that picks up the sounds in your immediate environment.
It processes this information into a pulse pattern to be emitted from the implanted electrodes. The external component can be removed as needed to be charged.
Who Can Benefit From Cochlear Implants?
Cochlear implants are typically used for those with severe hearing loss or those who are deaf. For those that are born deaf, the sooner a cochlear implant is acquired, the easier a time the child has to be able to utilize it.
Children’s brains are incredibly capable and flexible, which makes it easier for them to adapt to the implant. For an individual that is born deaf, a cochlear implant is the only viable option for them to hear.
Other people who may benefit from cochlear implants are individuals who no longer find hearing aids helpful and have severe forms of hearing loss. For individuals that grow up hearing and then get a cochlear implant, there is an acclimation period. During that time, some sounds may sound different and perhaps a little robotic.
Eventually, the brain can adapt and allow these cochlear implant recipients to regain some level of hearing that would otherwise not be possible.
Where a cochlear implant essentially hijacks every component of the ear, hearing aids help sound signals reach the inner ear at a volume that is perceivable. The nice thing about hearing aids is that these small electronic devices are much less invasive. Most styles of hearing aids can be utilized by nearly everyone.
Read on for a closer look at hearing aids, how they work, and different kinds of hearing aids.
How Do Hearing Aids Work?
All hearing aids attempt to increase the amount of sound that is detectable by the cochlea. A standard hearing aid accomplishes this by amplifying the volume of incoming sounds to a higher level.
This is helpful in standard age-associated sensorineural hearing loss because the hair cells in the cochlea can become less sensitive. By increasing volume, you allow the cochlea to perceive sounds that would have otherwise been outside of its hearing threshold.
Bone Conducting Hearing Aids
Bone conducting hearing aids are assistive hearing devices that consist of a microphone, a processing unit, and an oscillator. These devices can either be implanted or be placed on the bony prominence behind the ear—the mastoid process.
These devices take the signal from the mike and apply a vibration directly to the skull, which is then able to stimulate the inner ear. Effectively this helps by cutting out the need for the middle and outer ear altogether.
This type of hearing aid is less common than standard hearing aids, but it can be helpful for those that may be unable to use standard hearing aids due to ear malformations or other factors that would not allow them to utilize standard hearing aids.
Air Conducting Hearing Aids
Air conducting hearing aids are most likely the kind of hearing aid you are used to seeing and most familiar with. This common type of hearing aid has a microphone, amplifier, and speaker. The sounds that would normally enter the ear are detected by the microphone. They are then processed through the amp and emitted from the speaker at an adjusted volume.
These hearing aids are the most utilized because they are easier to utilize, require no surgery, and can provide immediate help to people to hear the sounds in their environment with a relatively small adjustment time frame. Plus, they have been around for quite some time and are much more affordable than other options.
Research Which Is Best For You
Cochlear implants and hearing aids are both hearing assistive devices, but they go about it in completely different ways. The main difference between the devices is wherein the physiology of hearing they intervene. Cochlear implants effectively cut out the need for the middle ear and directly stimulate the ear’s nerves in order for you to hear.
On the other side of the comparison, hearing aids simply try to make it easier for your inner ear to sense sounds by amplifying the vibrations leading to them. Another large difference is in price. A standard hearing rechargeable hearing aid like the EV1 will set you back about a hundred dollars, while a cochlear implant could cost tens of thousands of dollars.