Final answer:
Inner hair cells along the cochlea are responsible for sending signals to nerve fibers that form the auditory nerve and convey auditory information to the brain. These cells play a crucial role in the processing of sounds, with about 90 percent of auditory nerve fibers connected to them.
Step-by-step explanation:
The cells along the cochlea that send signals to nerve fibers which combine to form the auditory nerve are known as hair cells. Specifically, the inner hair cells are the primary transmitters of auditory information to the brain. They release an excitatory neurotransmitter when they bend due to the movement induced by sound waves through the cochlea's fluid. This neurotransmitter starts an action potential in the bipolar neural endings of the hair cells. These neurons send the signals along the auditory pathway to the central nervous system. About 90 percent of the auditory nerve fibers carry information from the inner hair cells. The outer hair cells are also involved in sending signals but are primarily responsible for amplifying and fine-tuning the response to sound frequencies through a feedback mechanism. The auditory nerve fibers then travel through the vestibulocochlear nerve to the cochlear nuclei in the superior medulla and continue through the brainstem, ultimately reaching the primary auditory cortex in the temporal lobe where the brain processes the auditory information.