The external auditory canal, also called the ear canal, is the passage that carries sound from the opening of the outer ear to the eardrum.
The external auditory canal extends from the opening of the ear to the tympanic membrane (eardrum), which separates the outer ear from the middle ear. It channels sound waves toward the eardrum as part of the normal air-conduction pathway. Its shape and dimensions also influence how certain sound frequencies reach the eardrum.
The canal is lined with skin and contains hairs and specialized glands in its outer portion. These glands produce earwax, also called cerumen, which helps trap dust and other small particles and protects the canal. A natural self-cleaning process gradually moves earwax and debris toward the opening of the ear.
Although earwax is protective, excessive accumulation can block the canal and interfere with sound transmission. Inflammation or infection of the canal, known as otitis externa, can cause pain, itching, and discharge. If swelling or debris significantly narrows or blocks the canal, temporary conductive hearing loss may occur.
QUICK FACT
- The external auditory canal is part of the outer ear, not the middle ear.
- Earwax is generally protective and does not need to be removed unless it causes symptoms, obstructs examination, or affects hearing.
- Inserting cotton buds or other objects deep into the canal can push earwax farther inward or injure the canal or eardrum.
COMMONLY CONFUSED WITH
- Eardrum (tympanic membrane): The thin membrane at the inner end of the ear canal that vibrates in response to sound waves.
- Outer ear: The external part of the ear, which includes the pinna (the visible part of the ear) and the external auditory canal.
- Middle ear: The air-filled space beyond the eardrum that contains the three small hearing bones called the ossicles.
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