What is the smallest bone in the human body?

The stapes or stirrup is a bone in the middle ear of humans and other tetrapods which is involved in the conduction of sound vibrations to the inner ear. This bone is connected to the oval window by its annular ligament, which allows the footplate to transmit sound energy through the oval window into the inner ear. The stapes is the smallest and lightest bone in the human body, and is so-called because of its resemblance to a stirrup.