International Licensing Examination (ILE) Practice Test

What energy transformation occurs in the cochlea?

1. Electrical to acoustic

2. Acoustic to hydraulic

3. Hydraulic to electrical

4. Mechanical to acoustic

The correct answer is: Hydraulic to electrical

In the cochlea, the primary energy transformation that occurs is from hydraulic to electrical. The cochlea is a spiral-shaped structure in the inner ear that plays a critical role in the process of hearing. When sound waves enter the ear, they cause the eardrum and subsequently the ossicles in the middle ear to vibrate. These mechanical vibrations are transmitted to the fluid (hydraulic energy) within the cochlea. As the fluid in the cochlea moves, it causes the basilar membrane to vibrate. This movement of the basilar membrane stimulates the hair cells, which are the sensory receptors located on the membrane. When the hair cells are displaced, they generate an electrical signal (nerve impulse) that is sent to the auditory nerve and ultimately processed by the brain as sound. This transformation from hydraulic energy (fluid movement) to electrical energy (nerve impulses) is essential for the perception of sound, making hydraulic to electrical the correct identification of the energy transformation occurring in the cochlea. Understanding this process is crucial for comprehending how the auditory system works, particularly in relation to hearing disorders that can arise from disruptions at any stage of this transformation.