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Which parts of the external auditory canal are made of cartilage and bone?

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Cross-section diagram of the human ear showing the outer ear, middle ear, and inner ear, with labeled parts including the auricle, auditory canal, tympanic membrane, ossicles, cochlea, semicircular canals, and nerves. — human ear Structure of the human ear.

The external auditory canal is a slightly curved tube that extends from the auricle to the tympanic membrane. Its wall is composed of two different materials along its length:

Cartilage: This makes up the outer third of the canal wall.12
Bone: This makes up the inner two-thirds of the canal wall.12

The entire passage is approximately 1 inch (24–25 mm) long and is lined with skin, which also covers the outer surface of the eardrum.12