Children whom are sensitive to sound are often times sensitive to loud, and/or high pitch sounds. There can be several reasons for this and it’s not always a straightforward answer. However, one contributing factor that we find at www.hmlfunctionalcare.com is that the child may have a retained Moro reflex.
The Moro reflex is a primitive reflex that appears prenatally and is supposed to integrate (go away) by 4-6 months of age (depending on the text you read). The Moro reflex is the reflex you see when you take your baby and lay them on their backs, and they may flail their arms and legs out. This may also cause them to cry or if they were sleeping, they may wake up. There are 28 or so other primitive and postural reflexes, 10 of them wreak havoc on the nervous system if they stick around when they aren’t supposed to.
See our previous post on https://hmlfunctionalcare.com/fidgety-kids/ to learn more about why primitive reflexes stick around. Specific exercises or stimuli may be needed to remediate the active Moro reflex. Some patients need one type of exercise, while others may need multiple brain-based exercises.
The Moro reflex “lives” in the midbrain of the brainstem. The midbrain is where our fight or flight sympathetic nervous system lives. The sympathetic nervous system is actually a network of many areas in the brain involved in our sympathetic responses but for simplicity, the bulk of its “lives” in the midbrain. Having an active Moro reflex keeps the midbrain at a heightened state (close to threshold) and can make the child easily startled by loud sounds, high pitched sounds, and even sudden movements across their field of vision.
Another reason why a child may be sensitive to sounds is that the sounds are higher pitched, instead of low pitched. The left brain processes high pitch sounds, the right brain processes low pitch sounds. Now, please keep in mind when we say the “the left brain does this, the right brain does that,” it’s not that both sides are not processing. It means where the majority of the processing is occurring, or where is the end-point processing occurring. If you have a child that is what we call “right brain weak” or that side of the brain is not quite developed as well as it should be, this too can contribute. The reason is that if the left brain is overly developed for the child’s age, their ability to process high pitch sounds may be at a heightened state (close to threshold) like the midbrain can be. See our brain chart to learn more: https://hmlfunctionalcare.com/wp-content/uploads/2020/04/brain.pdf
There can be other reasons why a child is overly sensitive to sound. At HML we strive to find the cause and correct it. This can entail auditory tone-based therapies, blocking sound from entering one ear over the other, suggesting certain tones or music to be played at home, or while sleeping, etc. What we’ve learned is that each child, and adult patient for that matter, is different and each sound sensitive person could need something entirely different than the other. And we will do our best to figure out how to help yours!