Unilateral hearing loss in children: No big deal? Not so fast!
My daughter is a bright, curious, outgoing child who loves school. She also has a unilateral hearing loss in the moderately severe range.
We do not know what caused her hearing loss. We do know that she was not born with it. We took her for a hearing test when she was six weeks old, and she was within the normal range. But by age four, after a lot of ear infections and an adenoidectomy, another hearing test revealed a mixed moderate-to-severe hearing loss in the left ear. It could be that one of the viruses that caused one of the middle-ear infections also caused some damage to her inner ear. It is quite possible the semicircular canals were also affected, as she has difficulty with balance.
People often assume that unilateral hearing loss in children is not a serious problem, since the unaffected ear is "just fine". But research has shown that children with unilateral hearing loss are still at risk for speech and language delays and difficulty in school.
My daughter's hearing loss is in the moderately severe range. To put it in audiological terms, her hearing threshold in her left ear is around 60 dB, right about the level of the human voice in normal conversation. This means that, when we are talking to her, she can barely hear us with that ear. If there is any background noise, our voices may be drowned out completely. Once she was diagnosed, we realized we had been seeing a number of classic signs of unilateral hearing loss.
Here are a few examples:
- Inability to localize sound. A child with a unilateral hearing loss only hears certain sounds in the "good" ear, but to figure out where a sound is coming from, your brain needs information from both ears. When I played hide-and-seek with my daughter and she had trouble finding me, I would try to help her by coughing, fake-sneezing, or making some sort of other noise that would lead her to me. It did not help at all. Similarly, if she were in the living room and one of us called to her from a different room, she did not know which way to go to find us. we have trained ourselves to guide her to us by naming the room we are in.
- Getting freaked out by sudden loud sounds. It's not unusual for small children to be afraid of loud noises, but in my daughter's case, the reaction was one of extreme terror. And it wasn't limited to fireworks and thunder. The phone and the doorbell had a similar effect on her, especially if she was alone in the room when they rang.
- Turning the volume way up when watching TV or listening to music.
- Inattention to peripheral activity in her environment. If I was in the living room with her and she was engaged in some sort of activity on her own (coloring, working on a puzzle, playing with her dolls, etc.), I could get up and walk into the kitchen, or out the front door to get the mail, without her noticing. A few minutes later, she would realize she was alone, and that she had no idea where anyone else was, and would freak out. Once we learned to get her attention and tell her where we were going, all was well.
- Inattention to speech directed at her unless the speaker first got her attention. Just as we could walk in or out of the room without her noticing, we found we needed to say her name or tap her on the shoulder before telling her something; if not, we'd have to repeat it. We couldn't just say, "I'm going out to get the mail." We had to call her name first and make sure she was looking at us and understood that we were talking to her.
- Garbled repetition of new vocabulary. Once, while riding in the car (around age four), she called out, "Look, Mommy, a baguettes truck." My wife looked where she was pointing, and realized she was referring to a FedEx delivery van. On her sixth birthday, a friend gave her a Webkinz pet. She was unfamiliar with the whole Webkinz fad, and thought her friend had said, "It's a weapon."
- Anxiety and clinginess in noisy, crowded settings. If you've ever had the experience of flying to a foreign country where you don't speak the language very well and your ears pop while the plane is landing so you can't hear so well, you probably remember how disoriented and wrong-footed that experience made you feel. So you can imagine how a young child with a hearing loss (even if it's "just" a unilateral hearing loss) feels when she gets away from her familiar home base.
- Unusual level of fatigue after a half-day in day care or preschool. The brain accounts for only two percent of the body's total mass, but it burns about a fifth of its energy. The brain of a child with a hearing loss has to work much harder to process what's going on, and this can leave the child exhausted. My daughter (apparently, judging from the glowing reports from the teachers) held it together quite well during preschool, but then came home and had meltdowns and tantrums because she was so fatigued. Once we caught on to this and started planning after-school activities that allowed her brain a rest and didn't require her to do any listening, her after-school behavior improved dramatically.
Other than her difficulty accurately pronouncing new words, she did not show signs of a speech or language delay, although children with unilateral hearing loss are at increased risk for this. It could be that she would not have had trouble in this area in any case, or it could be that having a pediatric speech-language pathologist for a father prevented her from falling behind her peers. As Aslan tells Lucy in C.S. Lewis's The Voyage of the Dawn Treader, no one ever gets to know what would have happened. What I do know is that, from the moment my daughter was born, just out of habit, I interacted with her using all the therapeutic techniques I use in my work, and made sure she grew up in a language-rich environment. I fully intended to do this whether she had a unilateral hearing loss or not, because that's how I roll. I'm nerdy that way.
Soon after her diagnosis, we had her fitted with a state-of-the-art digital hearing aid (the nice thing about a unilateral hearing loss is that you get away with buying just one hearing aid instead of two). It cost a pretty penny, and my health insurance policy did not cover it, but we considered it a priority to get her the one that was the best fit for her needs. It can be programmed to enhance each frequency range to match her hearing loss profile and minimize distortion. It automatically filters background noise and focuses its microphone forward to pick up speech in noisy settings like parties and restaurants. It also has a special setting for listening to music. This was especially important to us, because she has shown a tremendous appreciation for music ever since she was less than an hour old.
In addition to her hearing aid, her school provides an FM amplification system for use in the classroom. The teacher wears a lapel microphone and transmitter, and a receiver plugged into my daughter's hearing aid delivers the teacher's voice through the hearing aid directly into her ear. This way, even when the teacher is across the room or facing away from her, the teacher's voice is going directly into her ear.
I am happy to report that my daughter is thriving and doing well in school (as I write this in the summer of 2010, she has just completed first grade). In fact, she is a much stronger reader and speller than her normal-hearing older brother was at her age. This is not to say that school is a cake-walk for her. So far, no one has invented a hearing aid that changes a child with a hearing loss into a child without a hearing loss. Even with her hearing aid and the FM system, she occasionally has trouble hearing, or gets a distorted version of what the teacher is saying. If she has an ear infection and has to go without her hearing aid for a week or so, or if the hearing aid is in the shop for repairs or adjustments, we notice a difference in her energy levels after school. Still, she has learned good coping strategies and uses her charming personality and intelligence (both the result of genetics and good parenting, of course) to great advantage. She will always have her unilateral hearing loss, and it will always be inconvenient, but it is unlikely to hold her back from doing whatever she wants to do.
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