Today’s guest post from undergraduate SLP in training, Jane Jusova, provides an introduction to pediatric cochlear implants.
Pediatric hearing loss may occur due to many reasons, which include being born with parts of the ear that didn’t form correctly and as a result don’t work well. Other problems can occur due to illness, including serious infections, such as meningitis, as well as accidents resulting in head injuries. Many children may have recurrent ear infections, causing a build-up of fluid in the middle ear, which can also cause hearing loss.
There are two major kinds of hearing loss that children can experience: conductive hearing loss and sensorineural hearing loss. Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the tiny bones called ossicles of the middle ear. This type of hearing loss can often be corrected medically or surgically. Sensorineural hearing loss on the other hand happens when the cochlea is not working correctly because the tiny hair cells are damaged or destroyed. Depending on the loss, a person might hear most sounds (although they would be muffled), hear in quiet spaces but not in noise, hear only some sounds, or hear no sounds at all.
Sensorineural hearing loss is almost always permanent and a child’s ability to develop typically may be affected by it. Hearing loss in children can have a harmful effect on their speech and language development. There are several effective treatments for sensorineural hearing loss, one of which is cochlear implants. Children who are deaf or severely hard-of-hearing can be fitted for cochlear implants.
A cochlear implant is a surgically implanted device that replaces hair cells in the cochlea and under the skin behind the ear for the purpose of providing useful sound perception via electrical stimulation of the auditory nerve to restore hearing to a severely or profoundly deaf individual.
Since the first cochlear implant approved by the US Food and Drug Administration in the early 1980s, great advances have occurred in cochlear implant technology. In the United States, roughly 38,000 children have received them.
Cochlear implants can be implanted in prelingually or postlingually deaf children. A good candidate for a pediatric cochlear implant is a child at least 12 months of age with severe to profound sensorineural hearing loss in both ears who demonstrates limited or no functional benefit from conventional hearing aid amplification.
Cochlear implant evaluation can begin prior to 12 months of age. There is a comprehensive testing performed by audiologists and speech language pathologists to evaluate candidacy for a cochlear implant.
Children who end up receiving cochlear implants require ongoing audiological management and otolaryngological follow up. Ongoing management by an audiologist includes programming the implant parameters and monitoring device performance from electrical threshold and dynamic range data. Electrically evoked auditory brainstem responses (EABR), middle latency responses (MLR), or acoustic reflexes (EART) may be used intraoperatively with stimuli delivered to the cochlear implant prior to leaving the operating room or postoperatively on outpatient basis to facilitate the fitting process. These objective measures can be particularly useful in children who are either difficult to condition or otherwise unable to respond consistently to the electrical stimuli used to program the speech processor.
Follow up audiological evaluations are required to assess improvement in sound and speech detection and auditory reception of speech following implantation. Medical evaluation by an otolaryngologist should be performed as needed to monitor the postoperative course and medical status of the child.
Approximately one month after surgery, the audiologist activates the implant. Weekly, then monthly, extending to visits three to four times per year, the implant settings are adjusted. Biweekly auditory therapy is recommended for each child. Therapy may take place either by team therapists or by other professionals in the school or community. Annual evaluations with the audiologist, speech language pathologist and social worker document the child’s progress and allow any concerns to be addressed.
In addition to facilitating the child’s development of sound awareness and sound discrimination, the role of SLP also includes providing parental education about cochlear implants to ensure that the parents understand the importance of device compliance. This includes asking parents to keep track of how many hours a day the child wears the device, explaining to the parents the input that the cochlear implants provide and the importance of assuring the child wears the device consistently, teaching parents how they can ensure that the child continues to wear the device (e.g., distracting the child if he or she reaches to pull out the device as a means of interrupting the behavior, using praise once the child stops trying to pull out the device, etc.,)
Children who have lost all or most of their hearing later in life will benefit tremendously from cochlear implants. They learn to associate the signal provided by an implant with sounds they remember. This often provides recipients with the ability to understand speech solely by listening through the implant, without requiring any visual cues such as those provided by lip reading or sign language.
Cochlear implants, coupled with intensive post implantation speech therapy, can help young children to acquire speech, language, and social skills. Early implantation provides exposure to sounds that can be helpful during the critical period when children learn speech and language skills.
- American Speech-Language Hearing Association. Degree of Hearing Loss.
- American Speech-Language Hearing Association. Working Group on Cochlear Implants
- American Speech-Language Hearing Association. Cochlear Implants and the SLP
- Koch, D.B. (2000). Hearing Loss & Cochlear Implants. The Children’s Hearing Institute.
- Niparko, J., Lingua, C., & Carpenter, R. (2009). Assessment of candidacy for cochlear implantation. In J. K. Niparko (Ed.), Cochlear implants: Principles & practice (2nd edition, pp. 313-345). Baltimore: Lippincott Williams & Wilkins.
- Papsin BC & Gordon KA. (2007). Cochlear implants for children with severe-to-profound hearing loss. New England Journal of Medicine, 357, 2380-2387.
- Peters, B.R. (2006). Rationale for bilateral cochlear implantation in children and adults. White paper available from Cochlear Americas.