Final answer:
Auditory hair cells in the ear use mechanically-gated ion channels to detect sound vibrations, which leads to depolarization and signal transmission to the cochlear nerve. The intensity of sound is determined by how many hair cells are stimulated.
Step-by-step explanation:
Auditory hair cells in the ear detect sound vibrations through mechanically-gated ion channels. These specialized ion channels are responsive to mechanical forces, such as pressure or tissue deformation. When sound waves enter the ear, they cause the stereocilia on the hair cells to move. This movement bends the stereocilia, which are connected to the mechanically-gated ion channels by hair-like tethers. As they bend, the channels open, allowing ions to flow in and out of the cell, leading to depolarization of the hair cell membrane. This depolarization results in a signal that is transmitted to the cochlear nerve, which sends auditory information to the brain.
The intensity of the sound is determined by the number of hair cells stimulated at a specific location within the ear. Inner hair cells are the primary receptors for hearing and are responsible for transducing sound vibrations into neural signals. Outer hair cells work to fine-tune the sound waves, essentially amplifying the vibrations to make the signal stronger for the inner hair cells.