I just read this great article from the ASHA website:
The Mind Hears: Tuning In With a Cochlear Implant
“Can you hear what I’m saying?”
by Susan Boswell
These are often the first words spoken when a cochlear implant recipient’s processor is turned on. And they have been a rite of passage for more than 36,000 people around the world who have received cochlear implants over the last two decades. Technological advances have brought dramatic changes in candidacy criteria, opening the door for more people with severe and profound hearing losses to choose this option.
When the U.S. Food and Drug Administration (FDA) first approved a cochlear implant with a single electrode for adults in 1985 and for children in 1990, only those who were almost completely deaf and could only perceive vibrations with a hearing aid could qualify.
Today, children and adults who were not candidates just two years ago may well be considered as candidates. The age of pediatric candidates has dropped from 2 years to as young as 12 months, and eligibility criteria for adults continue to expand.
A growing body of research has demonstrated that children who receive cochlear implants when they are very young make greater gains in acquiring age-appropriate language skills than children implanted when they are older. In response, the FDA recently approved cochlear implants for children as young as 12 months.
Changes in pediatric criteria have also resulted from changes in the adult criteria, said Carolyn Brown, associate professor at the University of Iowa. “We have seen adults with severe hearing losses do well with cochlear implants–better than they did with hearing aids. As the average performance levels with a cochlear implants increase, we have started implanting patients with more hearing.”
Infants are candidates for cochlear implants only after it is determined that they are not making progress in acquiring language using powerful hearing aids. “For infants with severe-to-profound hearing loss, you have to teach them to understand the meaning of sound and then compare whether they function as well as a child with a cochlear implant. If they cannot function as well as children with implants, they are candidates.” said Margo Skinner, director of the cochlear implant program at the Washington University School of Medicine in St. Louis.
Cochlear implants differ from hearing aids in bypassing the damaged hair cells in the cochlea and directly stimulating the auditory nerve, Skinner explained. Some speech sounds, such as “ed” or “s,” are never heard by children with severe-to-profound hearing losses because hearing aids cannot make the sound loud enough, or because there are no longer cochlear hair cells left to transmit the sound.
“Often when kids get a cochlear implant, the first change you’ll see is the ability to pick up the ‘s.’ They hear these soft speech sounds–and it’s so evident,” Skinner said.
But cochlear implants do not hold a miracle cure for deafness. “There is a lot of variability in cochlear implant outcomes,” emphasized Karen Iler Kirk, coordinator of the cochlear implant program at the Indiana University School of Medicine. “Some children may find that the sound provided by a cochlear implant enhances their speechreading ability or makes them more aware of environmental sounds, while others can understand a great deal of speech through listening alone.”
Cochlear implants offer the opportunity for many young deaf children to acquire age-appropriate language skills, and they seem to acquire listening skills with less effort than do children who have profound hearing losses using hearing aids, Kirk said.