stapes stapes the stapes or stirrup is a bone in the middle ear of humans and other animals 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 (latin: stapes). stapesfrontal view of stapes (a), and view from below (b).detailspronunciation/ˈsteɪpiːz/precursor2nd branchial archpart ofmiddle earsystemauditory systemarticulationsincudostapedial jointidentifierslatinstapesmeshd013199ta98a15.3.02.033ta2895fma52751anatomical terms of bone this article is one of a series documenting the anatomy of thehuman ear outer ear auricle ear canal middle ear tympanic membrane ossicles malleus incus stapes inner ear vestibules utricle saccule cochlea semicircular canals structure