Ears begin to form early during fetal development. By the end of the first trimester, the basic structure of the ear is already in place. The outer ear, middle ear, and inner ear each have distinct roles in hearing and balance. The outer ear (pinna and ear canal) captures sound waves, the middle ear transmits these waves via the ossicles, and the inner ear (cochlea and vestibular system) converts them into electrical signals for the brain to interpret.
