The three smallest bones that are joined to each other in the human body are located in the middle ear and are referred to as the auditory ossicles: malleus (hammer), incus (anvil) und stapes (stirrup). Their job is to transmit incoming sound from the eardrum via the vestibular window to the inner ear and mechanically amplify the sound. The inner ear must be protected from lasting harm which can be caused by loud noise, this is achieved by a reflex that triggers muscle movement (stapedius muscle). causing the stapes to tilt for a short time and therefore sound can only be partially transmitted. If the auditory ossicles are shaken too vigorously (e.g. a sneeze or a cough), another muscle (tensor timpani) provides protection, by sticking to the hammer and tightening the eardrum. Otosclerosis is a typical condition that affects the auditory ossicles, causing them to stiffen, leading to increasing loss of hearing. In our model, you can see a cast and enlargement of original ossicles, created using micro CT.