SLP 1043: Anatomy of the Auditory System

Temporal Bone

• Houses the main auditory structures (outer, middle, inner)

Squamous Portion

it is the outer portion of the temporal bone which is flat and provides protection and attachment for muscles

tympanic portion

it is a portion in the temporal bone that forms part of the external auditorty canal, guiding sound waves toward the ear drum.

mastoid portion

it is a portion of the temporal bone that is spongy, air-filled bone behind the ear; connected to the middle ear and prone to infections also known as mastoiditis

petrous portion

it is a portion in the temporal bone that is the densest. it houses the ochlea and vestibular system, essential for hearing and balance

outer ear

part of the ear that functions as a sound collector that directs, amplifies and protects sound as it enters the auditory system.

Auricle

it is also called the pinna.
- it is a cartilaginous structure that aids in localization

• uses ITD and IDD for spatial hearing

• the ridges create a head shadow effect, aiding in identifying sound source direction

External Auditory Canal

also known as the meatus
- the outer part is 1/3 cartilaginous and the inner 2/3 is bony

• epithelial migration

• functions as a closed tube resonator (meaning it is open at one and closed in another)

Cerumen

also known as earwax
- acidic, deters insects and prevents fungal growth

• natural protection of the ear