system
Given the following post, respond as if you're commenting on Reddit:
human
Why can I make a rumbling noise by tensing something inside my ears?

Every time I ask someone if they can do it they think I'm crazy, does anyone know what this is and why I can do it?
gpt
What you are hearing is the tensor tympani muscle. This is a small muscle in your ear that acts as a dampener of external sound. It attaches to a small bone in the ear and prevents it from oscillating, particularly when chewing.  This is why you can also hear it if you move your jaw in certain positions, it also tends to contract when you close your eyes tightly and quickly. You'll notice the sound will only last briefly. This is because the initial contraction of the muscle causes the bone to move creating a rumbling sound. Interestingly, some people have the ability to contract this muscle voluntarily.