By Jane Madell, Au.D.
Hearing loss is the most common disability in children worldwide. Annually in America approximately 3 in 1,000 babies are born with permanent hearing loss, making hearing loss one of the most common birth defects in the U.S. Hearing loss cannot be viewed in isolation; it can cause problems for auditory brain development. When a child with hearing loss is born, the child has already had 20 weeks of auditory deprivation.
When babies with typical-hearing are born, they have been listening to their mother’s voice and the voices of others near their mother. They can tell the difference between their mother’s voice and their father’s voice. They recognize inflection; they can tell which words are important and separate them from words that are used to connect the important words. They recognize emotion in voices, and music they heard during pregnancy. Although the sounds they hear are softer and a little muffled compared with those heard outside the womb, they provide significant input to the auditory brain.
Babies with hearing loss
Babies with hearing loss are born with brain deprivation, which is why it is important to act quickly to reduce the effect of this delay. The critical thing to remember is that there is a short window for developing the auditory brain. If children do not get the opportunity to hear during the first 3 to 3 ½ years, they will lose that opportunity. We are not just talking about developing language (which is certainly critical), but also about literacy. Reading is in the same part of the brain as hearing, so if we want children to succeed, we need to build the auditory brain early.
Typical-hearing babies who are not exposed to language
Lack of exposure to auditory stimulation affects everyone’s brain. Typical-hearing children who live in homes where their parents do not talk with them will also show a lack of auditory brain development. Hart and Risley (1995) have demonstrated that the number of words heard directly affects both the number of words in a child’s vocabulary and the child’s IQ at age 3 years. Children who heard ~30,100 words in a 14-hour day had a vocabulary of ~1,100 words and an IQ of 117 at age three years, while children who heard ~8,600 words in a day had a vocabulary of 525 words and an IQ of 79.
So what should we be doing?
Every child needs good exposure to language. While professionals have a role, the most important people in providing language stimulation to children are their parents. Everyone who works with children needs to help parents understand that EVERY child needs a lot of auditory input. Parents need to be encouraged to talk, read, and sing to their children. Ten books a day should be the goal. We need to help parents learn how to talk to their children, and, most importantly, how to enjoy talking to their children. All children with limited language — not just those with hearing loss — have reduced economic possibilities.
Ears are the pathway to the brain; the brain is the organ of hearing. Just as parents are the people who need to feed their children and keep them warm, parents are also the people who have to give children power to use their brain. It is essential that parents are properly educated about their child's hearing loss and the role they play in their child's auditory development. If children can learn to listen and talk, they will be able to:
Talk to people around them and learn from them
Hear and learn great ideas
Read well and learn about the world
Receive a good education
Have life choices
The ability to get a good education and to increase life choices has the added advantage of reducing poverty, as well as the possibility of making major changes in a child’s life.
This post originally appeared on Hearing Health @ Hearing Health & Technology Matters’ blog on February 10, 2015. The author, Jane Madell, Au.D., is an audiologist, speech-language pathologist, and auditory verbal therapist with 40-plus years of experience in the greater New York City area.
*Typical Hearing was use in place of Normal Hearing.