What is the pathway traveled by the cochlear fluid pressure wave initiated by a sound wave?
The stapes transmits the pressure to the round window and from it to the perilymph of the scala vestibuli, which, in turn, sets up vibrations of Reissner’s membrane, resulting in a wave in the scala media.
The basilar membranes move next and transmit the pressure to the scala tympani and from there to the oval window.