A diagram of the right eardrum, from Gray's anatomy, via Wikipedia
The eardrums or tympanic membranes are a pair of cone shaped membranes which separate the outer ear from the middle ear. In a functioning ear, each vibrates in response to differing air pressure. It is attached directly to the malleus, which forms a bridge to the other bones in the middle ear that lead to the cochlea, which attaches to the auditory nerve.
Damage to the eardrum can cause conductive hearing loss, a form of deafness. The eardrum can be damaged by perforation, rupture, collapse or retraction.
In Holding On, House punctures the patient's eardrum with a hypodermic needle to draw out the blood from his persistent stapedial artery