The tensor tympani is a muscle within the ear. Its role is to dampen sounds, such as those produced from chewing. Contracting muscles produce vibration and sound. The sound is usually described as a rumbling sound
Slow twitch fibers produce 10 to 30 contractions per second (equivalent to 10 to 30 Hz sound frequency). Fast twitch fibers produce 30 to 70 contractions per second (equivalent to 30 to 70 Hz sound frequency). The vibration can be witnessed and felt by highly tensing one’s muscles.
Go to a quiet room and stick your fingers in your ears. What you will hear is the twitching of the muscle fibers in your arms. A rumbling noise. I can prove this by trying it again.
This time put your fingers in your ears and flex your arms. This time the noise gets louder. So you can listen to your own muscle cells twitching.