Cochlear Implants in Children
In some cases called a “bionic ear,” the cochlear implant uses the hope of getting or restoring the ability to sense sound for some people with considerable hearing loss.
What Is a Cochlear Implant?
A cochlear implant is a surgically implanted device that assists conquer problems in the cochlea (KO-klee-uh). The cochlea are snail-shaped, curled tubes near nerves in the ears. They change sound vibrations reaching the ear into signals that can be sent to the auditory nerve (or hearing nerve). The acoustic nerve then sends these signals to the brain, where they’re equated into recognizable noises.
If vital parts of the cochlea aren’t working as they must and the auditory nerve isn’t really stimulated, there’s no other way for the sounds to obtain to the brain. As a result, hearing doesn’t happen. This is called sensorineural hearing loss.
By entirely bypassing the damaged part of the cochlea, the cochlear implant uses its own electrical signals to promote the auditory nerve, enabling the person to hear.
” If you have a child who has severe hearing loss in both ears, implanting earlier is connected with much better language and speech outcomes and less of a gap versus kids with typical hearing,” states Kay W. Chang, MD, an associate teacher of otolaryngology at Stanford University and a pediatric cochlear implant cosmetic surgeon at Lucile Packard Health center of Stanford University in Palo Alto, Calif.
About Regular Hearing
The ear is comprised of 3 parts, and in normal hearing, sound go through all 3 on the way to the brain:
- The outer ear: This is the outer, noticeable part of the ear and the ear canal. When an individual hears a noise, the external ear catches the sound vibration and sends it through the ear canal to the middle ear.
- The middle ear: This consists of the eardrum and three small bones (the malleus, incus, and stapes). The sound vibration from the outer ear causes movement in these bones.
- The inner ear: This is where the cochlea are. The movement of the bones in the middle ear makes the fluid in the cochlea move, which promotes the hair cells (the countless small hearing receptors inside the cochlea). The hair cells bend backward and forward and send out chemical signals to the acoustic nerve, which carries these signals to the brain, where they’re analyzed.
Hair cells can be damaged or destroyed through aging, heredity, disease, infection, or duplicated or severe exposure to loud noise. If the hair cells do not work, the acoustic nerve can’t be stimulated and can’t send details to the brain. So, the individual will not be able to hear.
Hearing loss can be moderate, moderate, or severe, depending upon the number of hair cells that are defective, damaged, or ruined. Individuals with mild or moderate hearing loss may discover that hearing aids help (listening devices make sounds louder). Those with extensive or severe hearing loss might even have difficulty understanding loud noises. A listening devices will not help in these cases, so a doctor may advise a cochlear implant.
What a Cochlear Implant Does
The cochlear implant synthetically stimulates the inner ear area with electrical signals, which sends those signals to the acoustic nerve, letting a person hear.
Although sound quality from a cochlear implant is various from that in regular hearing, the cochlear implant lets somebody sense noise that she or he could not hear otherwise. And routine enhancements to the method the implants work are assisting to make the noise much more natural. Most infants, even if they never heard previously, will have the ability to make sense of these noises and develop speech and language.
A cochlear implant includes an implant plan, which is protected inside the skull, and a sound and speech processor, which is used externally (outside the body). Numerous components of the cochlear implant interact to receive noise, move it to the auditory nerve, and send it to the brain.
The cochlear implant bundle is comprised of:
- a receiver-stimulator which contains all the electronic circuits that manage the circulation of electrical pulses into the ear
- an antenna that receives the signals from the external sound and speech processor
- a magnet that holds the external sound and speech processor in place
- one wire including electrodes that are placed into the cochlea (the number of electrodes can differ depending upon the cochlear implant model type used). The electrodes act much like regular working hair cells and provide electrical charges to promote the auditory nerve.
The noise and speech processor is a minicomputer that processes sound into digital information, and after that sends out that info to the implant package through electrical signals. This is worn externally and looks a lot like a regular listening devices. Depending on the type of sound and speech processor used, it can either be used as a headset behind the ear or in a belt, harness, or pocket.
The noise and speech processor is made up of:
- a sound and speech processor (which can either be a body-level design that can be clipped onto clothes like a boom box, or an ear-level design that’s hooked over the ear).
- a microphone.
- a transmitter that sends out the signals to the cochlear implant bundle. The transmitter likewise consists of a magnet.
For the cochlear implant to work, the implant package and the sound and speech processor need to be lined up– that’s what the magnets are for. By lining up the magnets, both the implant bundle and sound and speech processor are secured and interact. If they aren’t entirely aligned, the device doesn’t work and the person cannot hear.
How a Cochlear Implant Works
Understanding how a cochlear implant works might help kids much better understand their new bionic ear and the cool technology behind it that permits them to hear much better.
Here’s how the implant works:
- The microphone picks up noise.
- Sound is sent to the sound and speech processor.
- The processor examines the noise and converts it into an electrical signal. (The signal includes details that determines how much electrical current will be sent to the electrodes.).
- The transmitter sends out the signal to the implant plan, where it’s deciphered.
- The implant plan identifies how much electrical existing need to pass to the electrodes and sends out the signal.
- The quantity of electric present determines loudness, and the position of the electrodes determines the sound’s pitch.
- The nerve endings in the cochlea are stimulated and the message is sent out to the brain along the acoustic nerve.
- The brain analyzes the sound and the person hears.
Cochlear Implant Surgery
Surgery for a cochlear implant takes 2– 4 hours and uses basic anesthesia (which keeps a patient totally unconscious). The surgeon will put and protect the implant plan under the skin and inside the skull, then thread the wires containing the electrodes into the spirals of the cochlea.
To protect the implant, the surgeon first drills a 3- to 4-millimeter bed in the temporal bone (the skull bone which contains part of the ear canal, the middle ear, and the inner ear). Then, the cosmetic surgeon opens the bone behind the ear to enable access to the middle ear. A small hole is drilled in the cochlea and the wires containing the electrodes are inserted. The implant package is then protected and the incision is closed with stitches.
After cochlear implant surgery, a child:
- will most likely have the ability to go home the next day.
- will have to use a dressing over the implant area for 24 Hr.
- may be off-balance or dizzy for a couple of days.
- might have mild to moderate pain (the doctor might advise offering pain medications).
- won’t have to have the stitches gotten rid of (they’re absorbable and dissolve on their own).
- can push the side of the cochlear implant in a few days.
About 2 to 4 weeks after surgery, the sound and speech processor is matched with the implant bundle and is programmed and fine-tuned to satisfy the child’s specific hearing needs.
Nowadays, children who are born deaf or with an extensive hearing loss in both ears can even get two cochlear implants, one for each ear, at the exact same time. This is a great advance as it requires just one surgery.
Discovering how to Use a Cochlear Implant
Because the hair cell damage, electrical signal patterns, and sensitivity of the auditory nerve are various for each individual, a specialist should tweak the sound and speech processor for every patient.
By determining the lowest and highest current for each electrode, the clinician discovers the softest and loudest noises that will be heard (each electrode produces a different sound with various pitch). The noise and speech processor matches sounds on different electrodes with various volumes and efforts to develop an accurate version of the original noise. Nevertheless, due to the fact that a minimal variety of electrodes are taking over the function of the countless hair cells in a typical ear, sounds won’t be totally “natural.” Nevertheless, infants who never heard previously will have the ability to make terrific sense of these noises and will rapidly learn language.
After the first couple of programming sessions, the user starts to pick up noises with the implant, but giving the implant full power is a progressive process that takes numerous months. In children who are born deaf, the stimulation from the implant will permit them to develop the brain paths required to hear sounds and establish speech and language. This is an extended process with programming and intensive therapy that frequently lasts for a number of years.
During the programming process, the user goes to speech and language therapy sessions to assist determine and interpret the new noises she or he is hearing. A fundamental part of the therapy is parent education and training.
Therapy will help a child establish and comprehend spoken language through spotting, imitating, and associating significances of sounds. These sessions last a minimum of a year, together with parent education and training programs. In most cases, therapy has actually helped kids with cochlear implants establish speech and language on par with their peers.
Some families decide to have implants in both ears. This can aid with speech detection when there is background sound.
Can an Implant Bring back Hearing for Everybody?
Cochlear implants are very effective for some people, but not everyone is a candidate to get one. Children 12 months of age or older with profound hearing loss in both ears are normally outstanding candidates, however not every child is qualified.
Typical reasons that a child may not be eligible for a cochlear implant include:
- the child’s hearing is “too great” (meaning the child can hear some noise and speech with listening devices).
- the hearing loss isn’t really due to an issue with the cochlea.
- the child has actually had extensive deafness for a very long time.
- the auditory nerve itself is harmed or absent.
Each potential prospect needs to be assessed by a cochlear implant team to see whether a cochlear implant is the best alternative.
Advantages of an implant can differ. The rehabilitation period can be long, and many factors (such as the condition of the acoustic nerve or the existence of scar tissue in the cochlea) can affect the success of the implant.
The doctor or cosmetic surgeon will assist parents understand what an implant can reasonably achieve for their child.