The incidence of hearing loss in children is higher than you might expect. Studies have shown that newborn hearing screenings identify from one to four out of 1,000 babies tested, depending on the research cited. Most hospitals offer newborn hearing screening and many audiologists offer the test in their office for the babies missed at birth. The babies may have hearing loss because of genetic causes, birth trauma, middle ear fluid, debris in the ear canals or even the side effect of medications given to the newborn. The reported incidence of hearing loss varies from hospital to hospital.
Causes of Hearing Loss
There are genetic and non-genetic types of hearing loss. There are two types of genetic hearing loss, syndromic and non-syndromic; and of these, 50 percent are recessive and 15 percent are dominant. The hearing loss is considered non-syndromic if it is the only issue the baby has. The term syndromic is used if there is hearing loss and other findings. Some genetic hearing loss will not show up until later in life. Twenty-five percent of babies with hearing loss are from non-genetic causes. The hearing loss might be from trauma before or during the birth process or a virus that can cause hearing loss. A baby with low birth weight is at risk for hearing impairment. If there is a history of hearing loss in the family that occurs at a young age then that baby has a higher risk for hearing loss. Hyperbilirubinemia (jaundice) that requires blood transfusion may cause hearing impairment. Older children get temporary hearing loss from ear infections, or permanent hearing loss from trauma to the head or from bacterial or viral infections.
Testing for Hearing Loss
Hearing screening is usually completed while the newborn is in the hospital. A test called an OAE (otoacoustic emission) is completed while they sleep. A small tip attached to a wire is placed in the ear canal. The tip houses a device that produces a sound that travels to the hearing organ or cochlea. If the cochlea is able to detect that sound, a tiny movement occurs which the tip records. If the baby does not pass, the screening is repeated at the age of two weeks. If the second screening is not passed, a diagnostic test is ordered. This test is called an ABR (auditory brainstem response) and provides information about the amount of hearing loss and the type of hearing loss. Again, the baby sleeps as tones go into the ear and a recording is generated. These tests are accurate enough that the initial hearing aids are programmed using this information.
Treatment for Hearing Loss
The treatment for hearing loss in children is similar to adults in that hearing aids are used. Because children learn so much about the world though language, it is important that the hearing aids are programmed well and are comfortable enough to wear all day. The parents play a significant role in the success of the child learning language and coping with the stigma of being hearing impaired. The parent’s attitude influences how the child views himself as he grows older. A positive self-image is important in learning how to deal with peer pressure.
Hearing impaired babies and children hear sound differently, making it important that they are exposed to speech and taught how to speak at a very early age. A speech pathologist will evaluate the baby’s speech development and design a plan for the parents to follow at home. Children spend the most time with their parents and learn the majority of their pre-school skills from them. If formal speech therapy is available that will start very early; the earlier, the better. Many insurance companies will help with the cost of this service.
Children use assistive technology to help focus on speech in a noisy room. In a classroom, the teacher wears a transmitting microphone which sends an FM signal directly back to the child’s hearing aids. These remote microphones provide a wonderful signal that has very little background noise embedded in it. If a child is able to use a remote microphone at home and in family social activities, or even TV viewing, the child has more opportunity to be successful learning language. Remember that hearing aids are not hearing cures, they simply aid (help) hearing. Deaf babies and children usually have a trial with hearing aids but if they do not benefit from the aids a cochlear implant (CI) is considered. We will discuss CIs for deafness in another article. FBN
By Dr. Karon Lynn, Au.D