Useless fact
The low rumbling sound heard in your ears when you tightly clench your jaw is caused by the contraction of the tensor tympani muscle.
Why this is true — Physiological studies confirm that voluntary or involuntary contraction of the tensor tympani muscle in the middle ear produces a low-frequency vibration heard as a rumble.
More useless facts
- The metal band that holds the eraser onto the end of a pencil is called a ferrule.
- The small extra pocket on the front of jeans was originally designed to hold pocket watches.
- The metallic smell on your hands after touching coins is actually a type of human body odor triggered by the chemical reaction with the metal.
- The wire cage that holds the cork in a bottle of champagne is called a muselet.