Final answer:
The cochlear canal, part of the inner ear, contains a fluid called endolymph which is vital for transmitting sound-induced vibrations to the organ of Corti, leading to the transduction of these vibrations into neural signals.
Step-by-step explanation:
The medium found in the cochlear canal, also known as the cochlear duct, is a fluid called endolymph. The cochlear canal is part of the inner ear structure, which includes the cochlea, a coiled tube that is essential for hearing. According to various figures and descriptions, when sound waves cause the stapes to press against the oval window, pressure waves are sent through the perilymph in the adjacent scala vestibuli and scala tympani. These waves ultimately cause the basilar membrane within the cochlear duct to vibrate, and this motion stimulates the hair cells in the organ of Corti. The movement of these hair cells transduces mechanical sound vibrations into electrical signals, which are then transmitted to the brain via the auditory nerve.