Ear canal
（重定向自Meatus acusticus externus）
The ear canal (external acoustic meatus, external auditory meatus, EAM) (Latin:meatus acusticus externus), is a tube running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about 2.5 centimetres (1 in) in length and 0.7 centimetres (0.3 in) in diameter.