Length of the external auditory canal is
EXTERNAL AUDITORY CANAL

It starts at the external auditory meatus and ends at the tympanic membrane, where a bony structure (bony outer attic wall at tympanic membrane, where ECA ends) projects, called scutum.
It is almost S-shaped curved canal of about 24 mm length.
It has - outer cartilaginous part (2/3rd) and - inner bony part (l/3rd).
It is directed upwards, backward and medially in the outer part and downwards, forwards and medially in the inner part.
The periosteum is very firmly adherent in EAC and hence even a minor infection like a furuncle is extremely painful.
20 mm
22 mm
24 mm
15 mm