Caroline is six years old, with bright brown eyes and, at the moment, no front teeth, like so many other first graders. She also wears a hearing aid in each ear’and has done so since she was three, when she was diagnosed with a moderate hearing loss.
For Caroline’s parents, there were many clues along the way. Caroline often didn’t respond to her name if her back was turned. She didn’t startle at noises that made other people jump. She liked the TV on loud. But it was the preschool she started attending when she was three that first put the clues together and suggested to Caroline’s parents that they have her hearing checked. The most significant clue to the preschool was Caroline’s unclear speech, especially the lack of consonants like “d” and “t” at the end of words.
So Caroline’s parents took her to an audiologist, who collected a full medical history, examined the little girl’s ears inside and out, ran a battery of hearing tests and other assessments, and eventually diagnosed that Caroline’s inner ear (the cochlea) was damaged. The audiologist said she had sensorineural hearing loss.
Caroline was immediately fitted with hearing aids. She also began receiving special education and related services through the public school system. Now in the first grade, she regularly gets speech therapy and other services, and her speech has improved dramatically. So has her vocabulary and her attentiveness. She sits in the front row in class, an accommodation that helps her hear the teacher clearly. She’s back on track, soaking up new information like a sponge, and eager for more.
About hearing loss in children
Hearing is one of our five senses. Hearing gives us access to sounds in the world around us’people’s voices, their words, a car horn blown in warning or as hello!
When a child has a hearing loss, it is cause for immediate attention. That’s because language and communication skills develop most rapidly in childhood, especially before the age of 3. When hearing loss goes undetected, children are delayed in developing these skills (March of Dimes, 2007).
Recognizing the importance of early detection, the Centers for Disease Control and Prevention (the CDC) recommends that every newborn be screened for hearing loss as early as possible, usually before they leave the hospital. Catching a hearing loss early means that treatment can start early as well and “help the child develop communication and language skills that will last a lifetime” (CDC, 2010).
Types of hearing loss
Before we describe the types of hearing loss a person may have, it’s useful to know that sound is measured by:
- its loudness or intensity (measured in units called decibels, dB); and
- its frequency or pitch (measured in units called hertz, Hz).
Hearing loss is generally described as slight, mild, moderate, severe, or profound, depending upon how well a person can hear the intensities or frequencies most strongly associated with speech. Impairments in hearing can occur in either or both areas, and may exist in only one ear or in both ears. Generally, only children whose hearing loss is greater than 90 decibels (dB) are considered deaf.
There are four types of hearing loss, as follows (eHealthMD, n.d.):
- Conductive hearing losses are caused by diseases or obstructions in the outer or middle ear (the pathways for sound to reach the inner ear). Conductive hearing losses usually affect all frequencies of hearing evenly and do not result in severe losses. A person with a conductive hearing loss usually is able to use a hearing aid well or can be helped medically or surgically.
- Sensorineural hearing losses result from damage to the delicate sensory hair cells of the inner ear or the nerves that supply it. These hearing losses can range from mild to profound. They often affect the person’s ability to hear certain frequencies more than others. Thus, even with amplification to increase the sound level, a person with a sensorineural hearing loss may perceive distorted sounds, sometimes making the successful use of a hearing aid impossible.
- A mixed hearing loss refers to a combination of conductive and sensorineural loss and means that a problem occurs in both the outer or middle and the inner ear.
- A central hearing loss results from damage or impairment to the nerves or nuclei of the central nervous system, either in the pathways to the brain or in the brain itself.