The organ of equilibrium is the EAR, which is responsible for maintaining balance and spatial orientation. It is composed of three parts: the outer EAR, the middle EAR, and the inner EAR. The outer EAR collects sound waves and directs them to the eardrum, the middle EAR amplifies the sound waves, and the inner EAR contains the vestibular system, which is responsible for detecting changes in head position and movement.