Know this first. Hearing is like an "always on" function. It is the last sense to fade out of consciousness which is why people in comas sometimes report having to have been able to hear everything people were saying.
Many of us get noise trauma, but before the hair cell actually dies and you get hearing loss, the cochlea gets shocked and stops transmitting those frequencies.
This is a nerve. One side is the axon and the other side are the dendrites.
View attachment 32932
The signal goes from left to right, from the dendrites to the axon terminal. They say that nerve impulses are electrical, but they are really electro-CHEMICAL, meaning that the chemicals are ions and carry an electric charge, and that is how the signal goes down the axon, the part that goes through the myelin sheath. It is because of sodium and potassium switching places really fast down the axon. The sodium/potassium ion channels are what cause the electrical component of the impulse. However, at the tips of the little branches of the dendrites, there are complex key-hole type molecular receptors that cause different types of nerve impulse. They are called neuro-receptor sites. The dendrites of the nerve are connected to the axon terminal(s) of a preceding nerve, like this.
View attachment 32931
The impulse still goes left to right in this diagram.
Where they connect it looks like this:
View attachment 32933
The yellow thing is the axon terminal of the sending nerve and the green is the tip of one of the dendrites of the receiving nerve.
The things labeled Neuro-transmitters are the complex chemicals that send the message from one nerve to the next. These are the chemicals that anti-depressants manipulate. (anti-depressants that sometimes seem to cause tinnitus).
The dendrites can dynamically disconnect and re-connect, this is what is called neuro-plasticity, the ability for new nerve connections to form and old ones to disconnect. This is why we can learn new things and forget old things.
So when your cochlea gets shocked, it stops sending certain signals. Since your auditory system is always on, the nerve dendrites in your brainstem start "sniffing out" neurotransmitters because they are thirsty for neurotransmitters.
View attachment 32934
The brain stem is where all of your senses converge, even your eyesight, as well as everything coming and going from your body, so there are certainly plenty of other nerve axon terminals that are actively secreting neurotransmitters there to "entice" dendrites to make connections. So the nerve from your auditory cortex in your brain that connects to the part in the brain stem gets bored from sudden loss of input and makes a new connection to something else, and that something else could be your heartbeat impulses, your eyesight, or just nonsensory "junk". So basically you start hearing electrical noise from some other places in your body. While these errant connections exist, the dendrites stay connected because they are getting their "fix" on neurotransmitters. You may even have dendrites from one nerve half connected to your auditory nerve, and half connected to some other place. They don't know or care that they are torturing you and driving you insane.
Back to when you sleep, your brain shuts off many connections to your body. Anyone that has experienced sleep paralysis knows what is like to wake up and not be able to move momentarily. The last sense to turn off, and it doesn't even really turn all the way off, is hearing.
So if you listen to this ridiculous noise that is all over the place spectrum wise and very random while you're asleep, then your cochlea, hopefully, probably, mostly recovered by now, will be sending impulses that will cause the axon terminal from the vestibulocochlear nerve in the brain stem to secrete neurotransmitters and the auditory nerve from the brain stem to the brain's dendrites will break up with the errant connections they have made that are probably turned off because you're asleep and "sniff out" the neurotransmitters coming from the vestibulocochlear nerve's axon terminal and reconnect.
That is why the sleep part is so import.
FYI this is really only a guess.
Member
