Time is everything. There is extraordinary data which shows that the younger a child is the more cortical real estate they have. In other words, the work we do early has a critical effect of what happens to a child. We know experience changes our brains. The video BRAIN POWER:From Neurons to Networks https://www.youtube.com/watch?v=zLp-edwiGUU helps describe What happens to the brain. When we say that a child is like a sponge, we mean that they can absorb so much – everything we expose them to builds their brains.

 

At birth, a child’s brain has about 100 billion neurons. In addition, they have synapses which make important connections within a child’s brain. In fact, a child’s brain has more connections than the entire internet. Adult brain have about 300 trillion links. Children’s brains have a quadrillion connections – more than the internet.

 

But connections are not present at birth. For a child who is receiving appropriate stimulation, 700-1000 new synapses or connections are developed ever second. In other words, every time you talk to the child, make eye contact, make a child laugh, you are growing their brain. The early years (birth to 5) are most critical because child’s brain makes as many connections as possible during that time and then prunes the ones it does not need. The connections we pay most attention do will be strengthened. Those we do not pay attention to will be pruned.

 

Brain Plasticity

Brain plasticity is greatest in early years and decreases with age. Babies brains need loving caring relationships to develop and grow. Early language skills are the foundation for literacy. The more words a child hears, the more words she will have at age 3. The Hart and Risley study demonstrate that fact. Children who heard about 30,000 words in a 14 hour day as babies had a vocabulary of 1,116 words at age 3 while children who heard only 8,624 words in a 14 hour day as babies had a vocabulary of 525 words at age 3.

 

Implications for children with hearing loss

The implications of this are really clear. We do not have time to waste. We need to provide auditory stimulation early and consistently if we expect a child to be able to listen and talk. You do not learn to be a tennis player by going to art school. You do not learn to listen and talk by learning sign language. Let me be clear. I am not saying that sign language will not build a child’s brain. It will build the visual connections but it will not build the auditory connections. If the goal of the family is to have a child use listening and spoken language, the child needs to be exposed to listening and to speech and language early. A child with typical hearing learns one new word every 90 minutes. If our children are going to do that we need to be sure that they have sufficient language exposure to be sure their brains are developing. Listening vocabulary results in speaking, reading and writing. The better you hear, the better you learn. Phonemic awareness is a critical part of literacy. The better a child’s listening skills, the better their phonemic awareness, and the better their reading and writing skills. Our goal is to have children reading at age level by grade 3.

 

What exactly do they need to hear?

They need to hear clear speech and a lot of it. Muddy In – Muddy Out. Years ago, one of my early supervisors had us try and draw the child’s audiogram before we tested a child, We needed to be able to hear what phonemes they were missing by listening to their speech. Muddy in – muddy out was very clear to me. And this skill has stood me in very good stead as a pediatric audiologist. It has helped be determine what I needed to do to adjust hearing aid and cochlea implant settings to improve perception.

 

What can we do to build listening skills

  1. Be sure technology is working and that a child is hearing well enough to develop the auditory brain.
  2. Encourage the child to listen. Don’t use visual cues first. Start with auditory – talk to the child, point to your ear and help him focus on what is being said.
  3. Point out sounds around you. “Did you hear the doorbell? Who is there? Let’s go look.”
  4. Listen listen listen. Remember the auditory sandwich. Start by saying it. Maybe say it again. If the child does not understand, use visual cues (maybe pointing or having them watch your face. Once they get the message remember to repeat it with just auditory access so the child builds the auditory – language connection
  5. Talk Talk Talk. Talk about everything that is happening in the child’s life. This will build theory of mind. ‘Uh oh, you dropped your ice cream. We made a mess. What can we do? We can’t eat it. I bet you are sad. Do you feel sad that your ice cream dropped?
  6. Give kids a turn. Don’t always lead the discussion. Don’t act like you know what your child is asking. If he just points to the frig. “Yes, yes that’s the frig”. You may know he wants juice but act like you do not. He has to give a little more if he is going to get the juice. Early on the word “juice” is enough. As his language grows, we expect “I want juice” or at least “want juice.” If we fill in the blanks for him, he does not have the need to build his skills.
  7. Expand language. If a child says “more juice” we say, “Do you want more juice? Okay.” Just pour a little so he has to ask for more. Build the need for him to use language.
  8. Read Read Read. A minimum of 10 books a day for starters. Use books, not just to read the words but to talk about what is happening. When you are reading a familiar book, ask what is going to happen next. Suggest a possible alternative. Maybe papa bear does not open the door. As kids get older and can read for themselves, parents should continue to read to and with their children. Discussing books is one of the most wonderful ways to build listening and literacy skills and to develop social skills.
  9. Try and keep the environment quiet. Turn off TV, radio, dishwasher. Work on language in the environment that will provide the easiest access. Your child with hearing loss will have the opportunity to build skills in noise. Unfortunately there is no choice about that, but to provide the best language learning, do it in quiet.

 

Time is critical. Build auditory brain skills early – before auditory connections are pruned and we cannot build the skills.

 

 

 

 

There was an interesting article in the January 2017 issue of Hearing Review in which Doug Beck interviews Anu Sharma about her work on auditory deprivation. Anu has done extraordinary work on this topic. We have know for a long time, from the work of Anu Sharma and others that significant hearing loss causes changes in brain activity, the auditory cortex and other brain structures.  

 

Mild hearing loss

Anu is now showing that even a mild hearing loss can have significant brain changes and cortical reorganization. She is demonstrating that the brain changes and re-organizes based on mild degradation of the stimulus or a mild lack of audibility.

If the brain is not receiving the full complement of sound, compensatory mechanisms engage to overcome the hearing loss. This might be more reliance on vision to supplement what was previously accomplished with hearing. Higher-order areas of the auditory cortex get recruited by vision and, slowly, they demonstrate functional changes. After the brain has made these compensations, Sharma has seen the pre-frontal areas of the brain become more active as auditory input is decreased.

 

What does this mean?

According to Sharma, this suggests that even with a mild sensorineural hearing loss, the brain has to extend more effort to listen, which changes cortical resource allocation within the brain. As hearing loss increases, the brain has to work harder to listen. The surprise for Sharma, (and the rest of us) is that these changes start much earlier than previously thought and can occur even with mild hearing loss.

We know that brain changes are not easily reversed so how should we interpret this data? There have been some case studies showing that early use of hearing aids for those with mild hearing loss slows down changes. Brains that do not show changes demonstrate better speech perception, and changes in neural networks are more likely associated with effortful listening.

 

Single sided deafness

Sharma reports on one child with single sided deafness who received a cochlear implant. Prior to receiving the implant, she had demonstrated cross modal recruitment from visual and somatosensory systems and her auditory pathway was not well organized. After receiving the implant, her cross-modal recruitment reversed and the auditory pathway contralateral to the CI ear started to normalize. For adults who can control where to look to listen to a person who is talking, a CROS hearing aid may provide sufficient help, but children will not have this skill and for them, a CI for the poor ear may offer the best result.

 

What should we do clinically?

Anyone who has worked in the field of hearing loss knows how hard it is to convince both adults and parents that mild hearing loss needs to be managed. How many times have I heard “He hears me most of the time. I’ll just stand near him. Hearing aids are so much trouble and I don’t want people to think of him as ‘different’”.

First, I give sympathy. I know this is difficult. It is not easy to have a child who has any issues. It is not what we planned for. But then I have to talk about what happens if we do not deal with the issues.

  1. We know that auditory deprivation leads to brain changes which may not be reversible.
  1. We know that even a mild hearing loss leads to academic difficulties. (Here is one of the good places to talk to families about what their goal is for their child is. “Where do you want your child to be at age 5, 10, 15, 20?” What does it take to get there?”
  1. What message are we sending to a child if we say that we do not want them to wear hearing aids? What are we saying about how we accept that child and his hearing loss?

These are questions we can discuss with adults too. I, for one, am not great about wearing my hearing aids all the time. I have excuses. I have RICD hearing aids so when I want to listen to books on tape as I often do when I a walking or on the subway I have to take the hearing aids out and put in earbuds. And of course “I manage.” I wear them when I need to listen. Well, that has to stop. I will wear my hearing aid more often. I promise. I cannot afford to lose any more brain activity.