The earlier deaf children get cochlear implants, the more likely they are to speak and comprehend language normally later in life, new research suggests. In fact, some doctors say doing the surgery in infancy may produce the best results.
In one study, children ages 12 months to 3 years showed rapid improvement in understanding speech during the first year after receiving one of the electronic devices, with the best results in the youngest children.
In another study, 43 percent of children who got implants at age 2 had normal oral language abilities at ages 8 to 9, compared with just 16 percent of youngsters who got implants at age 4, University of Texas Southwestern Medical School researcher Ann Geers found.
Geers said the longer implant use by the youngest children studied does not explain her results. Instead, she and other researchers say that very early childhood is an especially critical period in the development of language skills, during which children hear and imitate sounds around them.
Cochlear implants, typically implanted in one ear, use electrodes to transmit sounds to the auditory nerve and brain, bypassing nonfunctioning parts of the ear. The electronic devices are approved for use in children as young as 12 months, but some doctors have begun implanting them in even younger children.
“Babies spend quite a bit of time hearing and experiencing all kinds of sounds and speech in order to learn to talk,” said Dr. Nancy Young, an ear specialist at Chicago’s Children’s Memorial Hospital. “It certainly makes sense to think that giving children the opportunity to hear as soon as possible would be beneficial.”
The latest research did not look at whether putting implants in infants under a year yields better results than doing so at, say, 12 months or 18 months. And neither study looked at youngsters past age 9.
But Geers said she believes waiting until after age 2 may decrease the chances that a child will ever develop normal speech skills.
Better technology, improved hearing tests
Of the 50 or so children who get cochlear implants yearly at the Chicago hospital where Young works, the youngest was a 7-month-old Chesterton, Ind., boy with inherited hearing loss who had the surgery in December.
The boy, Kevin Johnston, is now a babbling, cooing 1-year-old year old and tests show his speech skills are “right on target” for a child his age, said his mother, Cindy Johnston.
Johnston said it was “a no-brainer” to have Kevin’s surgery so young. In the three-hour outpatient operation, a cochlear implant was installed in the baby’s right ear.
The same inherited condition affects her two older children, including a 4-year-old daughter who got an implant at 2½. “She’s just about a year behind in language,” Johnston said, a delay she said she thinks would not have occurred if her daughter had had the surgery earlier.
About 3 out of every 1,000 U.S. infants are born deaf. Deafness and hearing problems also can occur after birth from ailments including meningitis. Many such children are candidates for cochlear implants, as are some adults with age-related hearing loss.
Dr. Michael M.E. Johns, Archives editor, said tremendous advances have been made in dealing with hearing loss in children over the past decade, with better implant technology and improved hearing tests.
Newborn hearing tests, now performed in most states, mean most children born deaf are diagnosed shortly after birth. In the early 1990s, children born deaf were typically identified after age 3, Johns said.
An estimated 23,000 people nationwide have the implants, including some 10,000 children. The devices do not restore normal hearing, and users usually work with specialists to improve their communication skills. Many wear hearing aids in the non-implant ear; some also use sign language.
Some activists for the deaf have complained that the devices stigmatize deafness and a repudiation of sign language, but the implants are becoming more accepted.
“Opposition is giving way to the perception that it is one of a continuum of possibilities for parents to consider,” said researchers John Christiansen and Irene Leigh of Gallaudet University, a college for the deaf in Washington.