I think in the hustle and bustle of life, we forget to thank God for obvious blessings. Gifts like being able to hear, see, taste, smell, and speak. I recently posted about the physiology behind sight (https://wonderfullymade-kmk.com/how-do-our-eyes-see-color/). Today, I will talk about how we are able to hear speech.
There was a time when I thought the tympanic membrane (the ear drum) was so stinking cool. I just thought it was awesome; call me strange, I already know, haha. Does anyone else find cerumen extraction videos so satisfying? This leads me to this public service announcement: do not use Q-tips; they only pack your cerumen further down your ear canal. It even says on the back of the box not to put it in the ear canal. Have you been using Q-tips incorrectly? I digress on to our topic of the day.
God’s design of the ear and how it works
First, the sound is captured through our outer ear and travels to the middle ear, where our tympanic membrane (ear drum) is. After the tympanic membrane is a pocket of air; within it is three tiny bones. Connected to the middle ear is the eustachian tube that drains fluid and relieves pressure. The tympanic membrane vibrates, which causes these three bones to vibrate as well.
These three tiny bones are attached to the Cochlea, which is considered the inner ear. The name Cochlea comes from the Greek word “kochlias,” which means spiral or snail due to what its structure resembles. The middle ear bones vibrate the fluid-filled chamber in the Cochlea. Tiny hair cells within the Cochlea stimulate the auditory nerve, sending electrical signals to your brain to translate into perceived sound.
One of the chambers located in the Cochlea helps with your balance. The hair cells detect the movement of the fluid within the chamber, and then they send electrical signals to the vestibular nerve. The vestibular nerve communicates with the cerebellum underneath the brain’s occipital lobe. In the previous post, we discussed how music affects the cerebellum; I will link it here: https://wonderfullymade-kmk.com/creatures-made-to-worship/. These two nerves make up the eighth cranial nerve, called the vestibulocochlear. This cranial nerve’s function aids hearing, balance, posture, and spatial awareness.
Broca’s and Wernicke’s Area
One of my favorite things I learned in nursing school was about Broca’s and Wernicke’s areas. Wernicke’s area is your language comprehension area of the brain. Its location is in your temporal lobe. Wernicke’s area location is closer to the ear than Broca’s area. Because it is closer to your ear, it helps me remember that Wernicke is for comprehension of what you hear.
Broca’s area is your language production area. Broca’s area in the brain is located in the frontal lobe, closer to your mouth. I remember this because Broca sounds like Boca, and la boca in Spanish means mouth. Both areas are located on the dominant side, usually the left for most people. This is because the majority of people are right-handed. However, many left-handers also have these areas on the left side.
The brain can be divided into the left and right hemispheres. The caveat is that the right hemisphere affects the left side of the body while the left hemisphere affects the right side. Therefore, if someone appears with signs of right facial dropping, you can infer before imaging that their stroke more than likely occurred in the left hemisphere of the brain. I love neurology!
Real-life application
Whenever the unfortunate event of a stroke occurs, you can tell what area of the brain might be affected due to physical impairments and the way the person communicates. When I worked at the hospital, I worked in Neurology, and I found it so fascinating. Stroke patients are strong, brave, and resilient. Many of them take devastating news and come out stronger than they were before.
Once, I experienced someone who could comprehend what I was saying but could not speak due to aphasia. Aphasia is a loss of the ability to understand or express speech due to damage to the brain. So I grabbed some paper, and we wrote back and forth. That person’s stroke was in the Brocas area. So, they had Broca’s aphasia. Is that not so interesting?
The Gift of Hearing
I want to remind you how much of a blessing it is to hear. We can even begin to be grateful for the sounds that do not particularly bring us joy. For example, a baby’s cry is not the prettiest sound in the world. But what a relief it is to parents to hear the first cry after a baby’s delivery. We might hate to see and hear the sirens of a police car in our rearview mirror. But they let us know help is approaching after a sudden car crash.
We can speak negatively about many things, but let’s challenge ourselves to be positive instead because we can be thankful for all aspects of life when we change our perspective.
Lord, I thank you so much for the gift of hearing. Thank you for letting us hear birds sing and babies laugh. Thank you for letting us hear people preach the gospel and praise your name. Even though we do not thank you enough for these huge things in life, I pray we stop and thank you for these great gifts today. To you all glory and praise forever, Lord, Amen.
SOURCES
Huberman, A. (2023, September 18). How to use music to boost motivation, mood, & improve learning. Spotify. https://open.spotify.com/episode/0HRJGpDxVh29lMhMiWbc8l?si=s3fAH1VmQSeVSlr7Sw78dQ
Huberman, A., & Jarvis, E. (2022, August 29). Dr. Erich Jarvis: The neuroscience of speech, Language & Music. Spotify. https://open.spotify.com/episode/3u2YmYYI1r6WdJoIkBDlRW?si=FF3L7fPJRd6g95FPJx2Hng