Nov. 5, 2001 -- We may think of vision as our most important sense, and the worst one to lose. But hearing loss, especially early in life, can be far more devastating because it can profoundly affect a child's speech and language ability. Fortunately, new technology allows us not only to diagnose hearing loss in very young children, but also to treat it and prevent its devastating consequences.
Causes of Childhood Hearing Loss
The ear is made up of three sections: the outer, middle, and inner ear. Outer and middle ear problems can result in conductive hearing loss -- difficulty with the transmission of sound through the ear and into the brain. Problems with the inner ear can result in neural hearing loss, where the auditory nerves responsible for hearing are damaged. Although much more rare, this second type of hearing loss is more difficult to treat.
There are many identified causes of hearing loss in infants and children, including specific conditions (some of which are inherited), infections, and injury. But up to 40% of hearing loss in infants is unexplained.
Environmental noise is another serious threat to children's hearing. According to a study published in the July 2001 issue of the medical journal Pediatrics, more than 5 million American children aged 6 to 19 have some degree of hearing loss caused by loud noise.
Patricia Chase, PhD, a pediatric audiologist at East Tennessee State University's College of Public and Allied Health in Johnson City, TN, tells WebMD that she was surprised by these figures. "We often think of noise damage from work environments," she says. "With children, and adults too, you also have to take into account recreational noise, such as jet skis, boating, hunting... motorcycles, chain saws, weed eaters, lawnmowers ... and of course, music."
Recognizing and Diagnosing Childhood Hearing Loss
Early diagnosis is the key to minimizing damage in young children. With technological advances, we are now able to test for hearing loss in babies only a few hours old. "We can test hearing on very young and very uncooperative children," Robert W. Keith, PhD, professor of audiology and director of audiology at University of Cincinnati Medical Center in Ohio, tells WebMD. "[You] shouldn't wait if [you] are concerned that [your] child isn't responding to sound or speech, and language development is not developing according to normal landmarks. The house is on fire; you've got to get a fire truck there. You shouldn't wait, you're going to lose that critical language time."
According to Chase, signs that your infant might have hearing problems include not responding to sudden, loud noises and not looking around for Mother's voice when she talks out of the infant's range of vision.
Devices to Treat Childhood Hearing Loss
Treatment for hearing loss depends on its cause. According to William M. Luxford, MD, a specialist in otolaryngology and an associate of the House Ear Clinic at St. Vincent Medical Center in Los Angeles, most hearing loss caused by problems with the outer or middle ear can be treated with medicine (such as antibiotics to clear up an infection) or by cleaning out the ear canals. Occasionally, surgery is required to repair damage to the eardrum or the bones of the middle ear, or to place a tube through the eardrum to allow fluid in the middle ear to dry up.
Neural hearing loss requires a different approach. Many children with this condition can be fitted with a hearing aid, sometimes even during the first few weeks of life. Keith tells WebMD that hearing aids have improved dramatically in the last few years. The new digital hearing aids analyze sound through a computer chip to amplify voices and filter out background noise. Some can be programmed to meet an individual's particular needs and may have a volume control feature that automatically amplifies soft voices without ever delivering a too-loud sound to the wearer's ear.
Although rare, there are people with hearing loss so profound or complete that hearing aids will not help. Fortunately, these individuals might benefit from a cochlear implant. This surgically-implanted device has wires that go from an external hearing aid directly into the auditory nerve. While it does not restore perfectly normal hearing, the device does allow profoundly deaf people to experience sound.
"These things are a miracle," says Keith about cochlear implants. "Children who are profoundly deaf who have cochlear implants have a much greater probability of developing speech and language than they ever did [without one]." Recently, Keith spoke on the phone with a formerly-deaf man who'd had a cochlear implant.
New Technologies for Learning and Language Development
New devices are also being developed to help hearing-impaired children benefit from the typical classroom environment. All children learn speech and language by hearing it in their surroundings, so the goal of these devices is to get as much speech stimulation to hearing-impaired children as possible.
Deborah R. Price, AuD, an audiologist who is owner and founder of Hearing Professional Center in Dallas, recommends that children use a personal FM system. With this device, the voice of a parent or teacher who speaks into a microphone is delivered right into the child's ear. Older children who have already learned basic reading and writing skills also benefit from two-way messaging systems, which are essentially portable email devices.
An intriguing new product for hearing impaired children is a 3-D computerized tutor called 'Baldi.' This is an animated head complete with mouth, teeth, and tongue. Baldi helps teach language by speaking to children while making the appropriate facial movements. Unlike parents and teachers, he never tires of repeating the same words again and again.