Length of the external auditory canal is
20 mm
22 mm
24 mm
15 mm
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.