Current Federal Drug Administration (FDA) criteria for cochlear implantation in infants and children:
- Age 12 months or older
- For infants younger than 18 months, hearing loss must be profound in both ears (thresholds must be greater than 90 dB HL)
- For children 18 months and older, hearing loss may be severe-to-profound in both ears
- Hearing loss must be sensorineural (inner ear)
- The child must show limited benefit with appropriately fit hearing devices
- The child must show lack of progress with auditory skill development
- The child must be medically cleared for surgery
- The child must have no physical contraindications for surgery (can be determined from a CT scan)
- The family must have realistic expectations and be committed to follow-up appointments required after implantation
What is a Cochlear Implant?
A cochlear implant is different from a hearing aid. A hearing aid provides amplified sound to the ear canal, which is then sent through the ear to the auditory nerve. The auditory nerve carries the sound information to the brain. In children with significant hearing impairment, the sound that arrives in the ear is not enough for normal speech and language learning. A cochlear implant can provide a child with the sound they need.
The cochlear implant device is placed in the cochlea and under the mastoid bone behind the ear. The internal device is placed during surgery. Surgery is completed with general anesthesia, and the child is usually released from the hospital the same day.
As the incision is healing, the child will not hear sound from the implant. The implant must be coupled (connected) with external equipment and activated in order for the child to hear sound. The internal device is coupled to a microphone and speech processor worn externally. The external device is similar to a behind-the-ear hearing aid. The microphone picks up sound and changes it into a digital code. The digital code is sent along a small wire to a transmitter that is held in place by a small magnet in the internal receiver. The receiver inside the head alters the code into an electrical impulse, sending sound information to electrodes inside the cochlea. The electrical stimulation from the electrodes is sent along the auditory nerve, which connects to the brain. Sound is then able to bypass the damaged portion of the ear.
Cochlear Implant: Making the Decision For Your Child
Once significant hearing loss is identified, the family will be presented with options for communication and learning. These options range from American Sign Language (ASL) to aural/oral learning by way of listening and speaking.
The decision to move forward with a cochlear implant will depend on several factors as each child’s circumstances are unique. Families are strongly encouraged to talk with their child’s physician, audiologist, speech-language pathologist, therapist and educators, as they can provide additional insight and are familiar with cochlear implants.
Other families who have made the decision to pursue a cochlear implant for their child, as well as members of the Deaf community, can be helpful resources as the family collects information in order to make a decision.
Cochlear Implant Orientation and Evaluation
Prior to cochlear implant surgery, the child will need to be evaluated for cochlear implant candidacy, and the family will be given an orientation about the process and follow-up for cochlear implantation.
At this visit, the audiologist will test the child with and without hearing aids (depending on the child’s age), talk with the family about the cochlear implant and different devices available, and discuss appropriate expectations depending on the child’s hearing and health history. The audiologist will answer any questions the family may have about the cochlear implant process and what to expect following surgery.
Another decision the family will make is whether to pursue one or two implants for the child. The audiologist and physician will talk with the family about whether one or two implants will be recommended and which factors they should consider. If the child will be bilaterally implanted (two implants), the child can have both implants put in at the same time or a few months apart.
Cochlear Implant Medical Evaluation
An ear exam and discussion will be scheduled with the otolaryngologist. The physician will take a thorough medical and family history and complete an exam of the head and neck. Risks for cochlear implant surgery will be discussed.
Part of the evaluation will include a scan of the temporal bone. This scan will allow the physician to see whether the inner ear structure is intact, detect any abnormalities that may present a challenge for surgery, and also help determine the cause of the hearing loss.
The physician may recommend additional evaluations by a speech-language pathologist, neurologist, geneticist, psychologist, ophthalmologist (eye specialist), occupational therapist, and/or physical therapist prior to recommending implantation for the child.
Risks of Cochlear Implant Surgery
As with any surgery, cochlear implant surgery does carry some risks. Our surgeon will explain these risks to you in detail and answer any questions you may have.
Expectations for Cochlear Implant Recipients
Before a child is implanted, the audiologist and physician must determine that the family has realistic expectations about the child’s outcome following surgery and that the family is motivated to ensure the child has appropriate support services for optimal listening and language learning. These expectations will be explained once the required exams are completed.
Cochlear implant performance depends on many factors. The family must be committed to follow-up therapy and care in order for the implanted child to develop listening and spoken language skills. Families play a very important role in the habilitation/rehabilitation of a child with a cochlear implant!
Cochlear Implant Activation
Two to four weeks following implantation, after the surgical site has healed, the child will be scheduled with the audiologist for the initial activation of the implant. The device will be connected to the computer, and the implant will be stimulated a few electrodes at a time so that the child can hear sound. The audiologist will also use responses measured from the auditory nerve in the office to set the levels of the implant. Once levels are set through the computer, the implant is activated—all sound entering the microphone will be stimulating the implant.
The auditory stimulation will be new and possibly concerning for young children. Reactions to the implant may range from remaining silent, to crying and trying to knock the external implant off. Parents will practice putting the external speech processor on the child, using special pieces that help keep the processor on the ear. As the child adapts to wearing the implant over several weeks and months, the brain learns to hear and understand electrical sound. Depending on expectations set prior to surgery, the patient can learn to detect, discriminate, identify, and comprehend speech in different listening environments over time.
Cochlear Implant Follow-Up Services
Once the cochlear implant has been activated, the audiologist will program the implant with several different maps containing increasing levels of sound. The family will be instructed to progress through these maps to increase the sound window for the child, so that environmental and speech sounds can be heard through the implant.
It is important that the child has regular follow-up programming or mapping services so that levels are set optimally. The audiologist will explain when follow-up appointments should occur so that the child is seen at the appropriate intervals.
Cochlear Implant Troubleshooting
Although the external equipment for cochlear implants is designed to be durable and last a long time, occasionally equipment can need repair. For cochlear implant patients, it is important to know how to contact the customer service department at their respective manufacturer for help troubleshooting their device.
If the patient believes the equipment may be broken and in need of replacement, they should first try troubleshooting with the backup speech processor. If hearing improves with the backup processor, the patient should contact the manufacturer to see about diagnosing the equipment problem. More information can be found in the user manual for the processor.
If hearing does not improve with the backup processor, the patient should contact the audiologist immediately to report the issue.
Call Texas ENT & Allergy at (979) 693-7419 for more information or to schedule an appointment.