Final answer:
The cochlea is responsible for converting mechanical energy from sound waves into the electrochemical energy of neural impulses.
Step-by-step explanation:
Sensory transduction is the process by which a sensory stimulus is converted into electrical energy in the nervous system through a change in membrane potential. In the context of auditory stimuli, which are sound waves, this energy reaches the outer ear and the vibrations of the tympanum are sent to the middle ear. Here, the three bones of the middle ear, including the stapes (stirrup), play a pivotal role.
The stapes transfers the mechanical energy to the oval window of the cochlea, the fluid-filled part of the inner ear. The cochlea, containing the basilar membrane and hair-like projections known as stereocilia on hair cells, activates receptors that send auditory neural signals to the brain. Thus, it is within the cochlea where the conversion of mechanical energy to electrical signals occurs.