Question

Write a short note on-ear ossicles.

Answer 1

The ossicles (also called auditory ossicles) are three bones in either the middle ear. They are among the smallest bones in the human body. They transmit a vibration in the form of acoustic waves. The ossicles give the eardrum a mechanical advantage.

Complete step by step answer:
A flexible chain of three middle bones called ear ossicles is found in the middle ear. There are malleus, incus, and stapes of the three ear ossicles. The malleus, incus, and stapes are also known as the hammer, anvil, and stirrup respectively. The handle of the malleus is connected to the umbo-called central portion of the tympanic membrane. The other end of the malleus is connected by ligaments to the incus. The incus is associated with stapes. Stapes, in particular, is connected to the inner ear's oval membrane, fenestra ovalis. The ossicles of the ear act as a lever that transmits sound waves from the inner ear to the outside ear. They help to communicate sounds to the fluid-filled labyrinth (cochlea) from the air.
As sound waves vibrate the tympanic membrane (eardrum), in turn, pushes the nearest ossicle, the malleus, to which it is connected. The malleus then transmits the vibrations to the staples, through the incus, and thus ultimately to the membrane of the fenestra ovalis (oval window), the opening of the inner ear vestibule.
In order to improve the transmission and reception of sound, the lever action of the ossicles changes the vibrations and is a form of impedance matching.

Note: A mild to extreme hearing loss will constitute the absence of the auditory ossicles. The word "ossicle" literally means "small bone". However, the magnitude of the activities of the ossicles is monitored (and constricted) by two muscles connected to them (the tensor tympani and the stapedius). It is assumed that these muscles can contract to dampen the vibration of the ossicles, in order to protect the inner ear from overly loud noise and that they provide better frequency resolution at higher frequencies by reducing the transmission of low frequencies. In bats, these muscles are more highly evolved and help to obstruct the bats during echolocation (SONAR) outgoing cries.