As with adults, hearing loss in children is measured in degrees. The loss can range from mild – one that causes difficulty hearing hushed tones such as a whisper, to moderately severe – where the child can still hear loud speech, to a more profound loss resulting in deafness. Often, more mild hearing losses or unilateral (one-sided) hearing losses are not identified until the child starts exhibiting speech, language or learning delays. Unfortunately, many times, this is not noticed until school age, which means they may be starting school at a disadvantage.
Hearing loss in children typically falls into two main categories. The most common is a conductive hearing loss. This happens when something blocks the transmission of sound to the inner ear. Causes of a conductive hearing loss could be: an ear infection, fluid in the middle ear, impacted earwax, a perforated eardrum, a foreign object in the ear canal, or birth defects that alter the canal or middle ear structures. Many of these conditions are treatable through medication, minor procedures or surgery.
Sensorineural loss, sometimes referred to as “nerve deafness”, is the second type. This occurs when there is damage to the inner ear or nerve pathways from the inner ear to the brain. In children, this is most often congenital. It can also be caused by the use of ototoxic drugs (drugs that are harmful to the ear). Ototoxic drugs are typically prescribed to babies or very young children born with a serious illness or infection, or a child that is premature and has a very low birth weight. The risks of these drugs are well known and they are only chosen when necessary for preventing a more dangerous condition or saving the child’s life.
There are also a number of other medical conditions that can result in sensorineural hearing loss. Although there is no cure for this type of hearing loss, in most cases children can be helped with hearing aids and if they have a more profound loss, a cochlear implant. Providing the child with the appropriate amplification device prior to one year of age can insure the highest opportunity for normal speech, language and learning development. The goal for those children identified at birth is to have hearing aids prior to six months of age or a cochlear implant nearing one year of age.