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How Hearing Loss Can Change a Child’s Brain

Did you know that approximately 1.4 babies out of every 1000 have hearing loss, and according to the Centers for Disease Control and Prevention (CDC), 14.9% of children age 6 to 19 years have at least some hearing loss?  Whether it’s due to noise exposure, genetics and injury, or something else, early detection of hearing loss is critical.
Up until now, the focus has been on those children with deafness, but new research indicates that any level of hearing loss can affect a child’s brain and development.
The risk of hearing loss
Hearing loss in children can be a whole different ball game than hearing loss in adults. This is because children’s language and social development are so deeply rooted in hearing. Untreated hearing loss has been shown to impact social interaction and development, delay language and speech, and even leave children struggling academically. Early intervention is critical in avoiding these concerns.
But, do children with mild to moderate hearing loss face the same risks or just those with severe or profound hearing loss?
The research
New research led by Dr. Lorna Halliday, now at the MRC Cognition and Brain Sciences Unit, University of Cambridge, suggests that any level of hearing loss could lead to changes in how the brain processes sound. This, in turn, could pose developmental risks for the child.
The research team worked with 46 children diagnosed with mild to moderate hearing loss. An electroencephalogram (EEG) was used to measure their brain responses while they were listening to sounds. Dividing the children into two age groups (8-12 years old and 12-16 years old), researchers compared their results with those of children with normal hearing.
The results were not surprising. Those in the younger age group showed results similar to normal-hearing children their age, but those in the older group showed less response to sounds than those of normal-hearing children their age. The team repeated the test with the younger group several years later, finding consistent results. Their brain responses changed and were less than those of normal-hearing peers.
The team believes this is not due to a change in hearing loss but a change in how the brain works to hear sound with existing hearing loss.
“We know that children’s brains develop in response to exposure to sounds, so it should not be too surprising that even mild-to-moderate levels of hearing loss can lead to changes in the brain,” says Dr. Axelle Calcus, lead author of the paper, from PSL University, Paris. “However, this does suggest that we need to identify these problems at an earlier stage than is currently the case.”
The team believes that findings like these could help change how we diagnose children with hearing loss, and when hearing loss of any level is present, how we can better support them to foster strong language and social development.
If you believe your child has a hearing loss, contact our office to schedule a hearing evaluation today.
 
 

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The Importance of Child Hearing Screenings and Their Impact on Hearing Loss

Hearing loss is the number one congenital disability in the United States. Whether the hearing loss is congenital or an acquired hearing loss, the consequences of hearing loss can be devastating if left untreated. Even a slight hearing loss can cause speech and language delays that are considered to be educationally significant. These children can have emotional difficulties, perform poorly in school and can suffer from personal-social maladjustments. A child hearing screening is an essential tool in dealing with the loss of hearing. The school hearing screening’s impact on hearing loss is the subject of a new study.

The Problem

Children in North Carolina receive screenings only before the beginning of public school. This practice goes against the recommendations of several organizations guidelines that suggest testing throughout multiple grades. Because of this, hearing loss may go untreated in many children. Because of the potential negative impact of hearing loss on auditory learning and communication, researchers are looking at the effects that screening procedures have on outcomes.

Study Methods

1.181 children in grades kindergarten through ninth grade received a screening at a charter school during the fall of 2016. Two years after this, 862 children in grades kindergarten through eighth grade underwent testing to replicate the previous study findings and to collect additional data if possible. Two hearing healthcare professionals, two speech-language pathologists, and a large group of graduate students took part. The protocol for the screening includes:

  • All children in the study receive a screening at 1, 2, 4, and 6 kHz at 20 dB HL with a minimum of two stimuli before recording a response or no response to the stimuli.
  • The children who fail at least one frequency receive rescreening at 20 dB as a check for reliability. The examiners remove the headphones and reinstruct the child.
  • Any failure to respond at one or more frequencies in either ear is a failure at 25 dB HL.
  • A rescreening of children within three weeks by a clinician who is not familiar with the initial results will need scheduling and a referral for a diagnostic evaluation if they do not pass the rescreening is also a possibility.
  • A hearing healthcare professional will administer otoscopy and tympanometry on all children who fail the initial screening.

Results

According to the conclusions of the study, a comparable number of children failed the screenings for pure tone in 2016 and 2018. This finding suggests that the results are replicable. All of the children failing the rescreening were part of distribution across grades with the majority of failures concentrated in third grade in 2016 and fifth grade in 2018. The otoscopy and tympanometry findings were abnormal in four percent of the children in the 2016 screening and three percent in the 2018 testing. Those students passing the pure tone rescreening at 25 dB received a referral for medical intervention. The results indicate that the screening criterion increases the failure rate of the initial screening.

Indications

The study indicates that a school-wide hearing screening can identify more children with potential hearing loss. More research should take place to recommend universal screening criteria. Although the authors recommend diagnostic testing following a screening, the study indicates that parents are not prone to follow up even when the testing is free. These and other barriers to compliance must receive exposure.