How does the outer ear collect sound waves?

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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 outer ear collects sound waves through the auricle—also known as the pinna—which is the visible, cartilaginous portion of the ear that projects from the side of the head.123

The auricle features an irregular, funnel-like shape formed by various ridges, furrows, and hollows. Together with the concha, which is the deepest depression at the entrance to the external auditory canal, the auricle helps to capture sound waves from the environment and funnel them into the canal.14

Once directed into the external auditory canal, the sound waves travel toward the tympanic membrane. The canal itself further assists in the process by providing resonance enhancement, which increases the amount of sound reaching the eardrum, particularly for frequencies between 2,000 and 7,000 hertz.425