Voluntary Control
Contracting muscles produce vibration and 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, as when making a firm fist. The sound can be heard by pressing a highly tensed muscle against the ear, again a firm fist is a good example. The sound is usually described as a rumbling sound. Some individuals can voluntarily produce this rumbling sound by contracting the tensor tympani muscle of the middle ear. The rumbling sound can also be heard when the neck or jaw muscles are highly tensed as when yawning deeply. This phenomenon is known since (at least) 1884 (cf : Tillaux Paul Jules, Traité d’Anatomie topographique avec applications à la chirurgie, Paris Asselin et Houzeau publishers (4°ed. 1884, p. 125 )).
Read more about this topic: Tensor Tympani Muscle
Famous quotes containing the words voluntary and/or control:
“Men are not therefore put to death, or punished for that their theft proceedeth from election; but because it was noxious and contrary to men’s preservation, and the punishment conducing to the preservation of the rest, inasmuch as to punish those that do voluntary hurt, and none else, frameth and maketh men’s wills such as men would have them.”
—Thomas Hobbes (1579–1688)
“The awareness that health is dependent upon habits that we control makes us the first generation in history that to a large extent determines its own destiny.”
—Jimmy Carter (James Earl Carter, Jr.)