Source: Richard Glickman-Simon, MD, Assistant Professor, Department of Public Health and Community Medicine, Tufts University School of Medicine, MA

This video describes the examination of the ear, beginning with a review of its surface and interior anatomy (Figure 1). The cartilaginous auricle consists of the helix, antihelix, earlobe, and tragus. The mastoid process is positioned just behind the earlobe. The slightly curving auditory canal ends at the tympanic membrane, which transmits sound waves collected by the external ear to the air-filled middle ear. The Eustachian tube connects to the middle ear with the nasopharynx. Vibrations of the tympanic membrane transmit to the three connected ossicles of the middle ear (the malleus, incus, and stapes). The vibrations are transformed into electrical signals in the inner ear, and then carried to the brain by the cochlear nerve. Hearing, therefore, comprises a conductive phase that involves the external and middle ear, and a sensorineural phase that involves the inner ear and cochlear nerve.

The auditory canal and the tympanic membrane are examined with the otoscope, a handheld instrument with a light source, a magnifier, and a disposable cone-shaped speculum. It is important to be familiar with the tympanic membrane landmarks (Figure 2). Only two of the three ossicles - the malleus and incus - can normally be seen; the malleus is near the center, and the uncus is just posterior. A cone of light can be seen emanating downward and anteriorly from the umbo, or point of contact between the membrane and the tip of the malleus. The short process roughly demarcates the boundary between the two regions of the tympanic membrane: the pars flaccida, lying superior and posterior, and the far larger pars tensa, lying anterior and inferior. Normally, the tympanic membrane is pink-gray in color and readily reflects the light of the otoscope.

Figure 1. Anatomy of the Ear. A schematic drawing of the human ear in frontal section with outer, middle, and inner ear structures labeled.