Final answer:
Sound waves enter the outer ear and vibrate the eardrum, which sends these vibrations through the middle ear bones to the inner ear. In the cochlea of the inner ear, mechanical energy is transduced into electrical impulses by the basilar membrane and stereocilia. The auditory nerve carries these signals to the brain where sound is interpreted.
Step-by-step explanation:
How Wave Propagation and Signal Transduction in the Ear Works
The process of hearing begins when sound waves, which are a type of pressure wave, enter the ear canal and impinge upon the eardrum, technically known as the tympanum. This sets the eardrum into motion, transferring the mechanical vibrations through the three tiny bones in the middle ear: the malleus, incus, and stapes, collectively known as the ossicles. These bones amplify the sound and convey the vibrations to the oval window, the entry point to the inner ear.
In the inner ear, specifically the cochlea, the mechanical energy is converted into electrical impulses. The cochlea, filled with fluid, has the delicate basilar membrane and stereocilia (tiny hair-like structures), which react to the fluid's pressure waves. Different frequencies of sound waves stimulate different regions of the basilar membrane, triggering the stereocilia to send neural signals through the auditory nerve to the brain, where they are interpreted as distinct sounds.
The complexity of the human ear makes it an excellent transducer, capable of converting the minutest variations in air pressure into a rich tapestry of audible information, from the nuanced tones of conversation to the ebbs and flows of music. This physical process of converting external auditory information into signals the brain can interpret is known as sound transduction.