The tensor tympani is a muscle within the middle ear. It automatically contracts in order to dampen loud sounds, usually ones produced in one’s head, such as chewing, coughing, and swallowing, but it also reacts to external noises like thunder.
Interestingly, while the tensor tympani’s reaction to loud sounds is completely involuntary, approximately 16% of the population can voluntarily contract this muscle, producing a low rumbling sound in their ears. Reportedly, many “ear rumblers” to block out annoying or disruptive sounds, though most cannot keep the muscle contracted for longer than a minute at a time.
All of that is to say, my headcanon with regards to Kryptonians is that they have exceptional control over their tensor tympani muscles, which they “rumble” in order to block out most of the sound that would otherwise be picked up by their superhearing.












