What is the difference between the inner and outer parts of the ear?

Although the inner and outer ear are both parts of the ear, they can generally be regarded as two different parts of the body, and as such completely different. The inner ear is the innermost part of the sound detection system, and the one closest to the brain. The outer ear is the outermost part, and includes the part of the ear that protrudes from the head and part of the ear channel. For a complete explanation, the best option is to use online resources as the Physics Classroom.