Leaving your AirPods in for any extended period of time can cause an overexposure to sound which damages the cochlea, the outer hair cells and the stria vascularis of the inner ear.
It turns out there's a similar process at play in your cochlea, deep inside your ear- where a tiny bony cavity houses the organ that allows you to hear.
Next, the sound makes its way to the cochlea, which is a hollow, spiraled bit of bone that's full of fluid and lined with thousands of microscopic hairs.
Kind of like a harp with many, many strings, the fibers near the base of the cochlea are short and stiff, while those at the end are longer and looser.
If you could unspool this little snail shell, and cut it in a cross-section, you'd see that the cochlea consists of three main chambers that run all the way through it, separated by sensitive membranes.
The highest frequencies, down to 20,000 Hz, go all the way to the bottom of the cochlea, and every other frequency is represented somewhere in between.