What is a cochlear implant?
A cochlear implant is a small electronic medical device that provides the sensation of hearing to individuals who have severe to profound hearing loss by directly stimulating the auditory nerve (the nerve for hearing). While it does not provide or restore “normal” hearing, it can provide children with hearing loss access to sound and spoken language.
A cochlear implant has two parts:
- Speech Processor: The external piece of the implant is the speech processor, which is typically worn behind the ear, similar to a hearing aid. The processor has a microphone that picks up sound and a computer that codes the sound into electrical signals. These signals are sent up a cable to a transmitting coil, held on to the side of the child’s head with a magnet. The processor turns sound into a code and sends this information through the skin to the internal device.
- Internal device: A surgeon implants one part of the device under the skin behind your child’s ear. This contains a thin wire with an array of electrodes. The coded signal from the processor is transmitted through the electrodes to stimulate the hearing nerve, taking over the function of damaged or missing cells that are unable to transmit hearing information themselves. That code is then sent through the auditory nerve in the form of electrical pluses which the brain interprets as sound.
Our center works with and services devices from all major cochlear implant manufacturers, including Cochlear Americas, Advanced Bionics, and Med-El. We also provide hearing aid services when needed.
Who can benefit from a cochlear implant?
The specialists at Valley Children’s Hospital are here to help you determine if a cochlear implant is the right option for your family. Children with hearing loss is in the severe to profound range where traditional hearing aids may not be able to provide enough volume or clarity to hear speech and environmental sounds could be considered candidates. Furthermore, children who are born deaf and are implanted early in life, or those who learned to talk before they suddenly or gradually lost their hearing typically have the best outcomes.
How will we know if my child is a candidate for a cochlear implant?
Our team conducts a thorough evaluation of your child before determining if a cochlear implant is the right treatment option for their condition. These evaluations include:
- Audiologic tests to determine the severity of hearing loss
- Hearing aid trial when needed to determine if amplification could help your child
- Consultation with the otolaryngologist (ENT)
- Imaging tests, such as CT or MRI to see the child’s inner ear
- Speech-language evaluation to evaluate speech development
- Social services evaluation to identify any special factors or care needs to address
Once these evaluations are complete, our team meets to discuss your child’s case and the appropriateness of a cochlear implant. We will contact you after this meeting to discuss our recommendations and plan the next steps. If an implant is not the right choice for your child, we will talk with you about other options.
How is a cochlear implant surgery performed?
Cochlear implant surgery is done at Valley Children’s Hospital. The surgery lasts three to six hours and is done under general anesthesia by the pediatric surgical team.
The surgeon will make a cut (incision) behind the ear to open the area where the implant will be placed. The surgeon will then place the electrode array into the inner ear (cochlea) and the electronic receiver under the skin behind the ear. Electrical recordings are done during surgery to show that the electrodes are providing stimulation to the nerve.
The incisions are then closed. Your child will be moved into the recovery area and watched closely. A child usually stays in the hospital one night after the surgery, and one parent or caregiver is encouraged to stay in the child's room during recovery.
How well can I expect my child to hear with a cochlear implant?
The primary goal of our program is to provide children with access to sound for the development or enhancement of listening and spoken language. While cochlear implants do not restore hearing to “normal,” they can vastly improve hearing and speech clarity.
There is a range in performance for cochlear implant users. Some children use the sound from a cochlear implant to aid lip-reading and sound awareness of environmental sounds (traffic, sirens, alarms). Other children hear well enough to develop and understand speech well in quiet environments. Some are even able to participate in their communication environment with little added effort.
Every patient progresses differently and it is a gradual process over time. While we cannot predict your child’s long term speech understanding, there are many factors that influence how well a child will hear with their cochlear implant. These factors include:
- Age at implantation: Children born with severe to profound hearing loss achieve significantly better listening and spoken language outcomes if implanted before 12 months of age.
- Speech processor use time: Children who wear the cochlear implant speech processors all waking hours hear all the spoken language and environmental sounds during their day, which leads to better outcomes compared to those who use it inconsistently.
- Previous auditory experience: Children who had listening and spoken language development and then lost their hearing typically have more favorable outcomes.
- Duration of deafness: Shorter length of deafness (i.e. implanted quickly after hearing loss is detected) is associated with better outcomes.
- Presence of other disabilities: Multiple disabilities can impact a child’s language outcomes. Since it is ideal to implant a child at an early age, there will be children who receive implants prior to the identification of additional disability.
- Anatomy: The more normal or typical the ear anatomy, the better the outcome. Children with abnormal inner ears or auditory nerves may not have the proper anatomy to hear well with a cochlear implant.
- Teaching approaches emphasizing auditory learning: Children who are participating in spoken-language-rich environments tend to have better outcomes.
- Commitment and motivation: A cochlear implant involves a lifetime commitment on the part of the patient and family to attend the multitude of therapy and audiology appointments. Additionally, the family will need to implement the recommended strategies at home.
- Having a support system: It takes a village. Deaf and hard of hearing children should be enrolled in an appropriate educational environment from a very young age. These teachers and therapists are there to support you and your child on this journey. Other family members should also be involved as much as possible to support the child as they develop.