Sound waves hitting the eardrum set it into motion. Trace the pathway of vibrations from the eardrum to the spiral organ of Corti, where the hair cells are stimulated.

Verified step by step guidance

1. The sound waves cause the eardrum (tympanic membrane) to vibrate. These vibrations correspond to the frequency and amplitude of the sound waves.
2. The vibrations are transmitted to the auditory ossicles in the middle ear: the malleus (hammer), incus (anvil), and stapes (stirrup). These bones amplify the vibrations and transfer them to the oval window of the cochlea.
3. The stapes pushes against the oval window, creating pressure waves in the perilymph fluid within the cochlea. These waves travel through the scala vestibuli, one of the fluid-filled chambers of the cochlea.
4. The pressure waves in the perilymph cause the basilar membrane to vibrate at specific locations depending on the frequency of the sound. High-frequency sounds vibrate the basilar membrane near the base of the cochlea, while low-frequency sounds vibrate it near the apex.
5. The vibrations of the basilar membrane stimulate the hair cells located in the spiral organ of Corti. The hair cells convert mechanical vibrations into electrical signals, which are then transmitted to the brain via the auditory nerve (cranial nerve VIII).

Key Concepts

Sound Wave Transmission

Sound waves are mechanical vibrations that travel through a medium, such as air, and are captured by the outer ear. When these waves reach the eardrum, they cause it to vibrate, initiating the process of sound transmission through the auditory system.

Middle Ear Structures

The middle ear contains three small bones known as the ossicles (malleus, incus, and stapes) that amplify and transmit the vibrations from the eardrum to the inner ear. The stapes connects to the oval window, a membrane-covered opening to the cochlea, facilitating the transfer of sound energy into fluid.

Organ of Corti and Hair Cells

The Organ of Corti, located within the cochlea, is the sensory organ responsible for converting sound vibrations into neural signals. It contains hair cells that, when stimulated by fluid movement caused by the vibrations, generate electrical impulses sent to the brain, allowing for the perception of sound.