The middle ear (the space immediately behind the eardrum) has two tiny muscles, called the stapedius and the tensor tympani, that normally limit movement of the eardrum in order to protect the ear from excessively loud sounds. However, if these muscles contract in an abnormal rhythmic pattern (“middle ear myoclonus”), the motion of the eardrum that they produce can be perceived as a sound (tinnitus). Usually, this occurs spontaneously, and sometimes, it can also cease spontaneously. The abnormal contraction of the eardrum can sometimes be observed by an examiner using a microscope or otoscope inserted in the ear canal, and it can sometimes be further characterized by a test (impedance tympanometry) that measures eardrum motion. Treatment includes watchful waiting, physical (zygomatic pressure), audiologic (masking), pharmacologic (a muscle relaxant such as orphenadrine), injection (onabotulinum toxin), and surgical (sectioning the tendon of the muscle to the stapedius or the tensor tympani).