An otoscope potentially gives a view of the ear canal and tympanic membrane or eardrum. It is imperative that visualization of an intact tympanic membrane (eardrum) is noted. It gathers sound energy and focuses it on the eardrum (tympanic membrane). Ear thermometers measure eardrum temperature using infrared sensors. Collapse or retraction of the eardrum can cause conductive hearing loss or cholesteatoma. Iraqi secret police broke his nose, dislocated his shoulder and punctured his eardrum. Rupture or perforation of the eardrum can lead to conductive hearing loss. The pinna serves to focus sound waves through the ear canal toward the eardrum. The result is a tympanogram showing ear canal volume, middle ear pressure and eardrum compliance. The malleus bone bridges the gap between the eardrum and the other ossicles. His phonautograph was constructed as an analog of the ear canal, eardrum and ossicles. The eardrum, middle ear, and inner ear are developed. The ear canal ends at the external surface of the eardrum. The ear is washed and a small incision made in the eardrum. Further weakness or perforation of the eardrum may occur.