Download The Human Ear and Simple Tests of Hearing

THE HUMAN EAR AND SIMPLE TESTS OF HEARING
Ear Anatomy
 Outer Ear
 Auricle, external auditory canal and the tympanic membrane
 Middle Ear
 An air filled space, ossicular chain
 Inner Ear
 Cochlea
PATHWAYS OF SOUND
Air Conduction
 Sound travels through the air and courses through the outer, middle and inner ear
 Auricle acts as a funnel to collect sound
 Sound waves hit TM and sets the bones into motion
 The bones tap cochlea, causing the inner ear fluid to move
 Fluid motion activate hair cells, sending signals to auditory nerve
 Auditory nerve fires, sending signal to brain
How the ear works
Sound traveling through ear
PATHWAYS OF SOUND
Bone Conduction
 Sound travels through bone vibration
 Bypass the outer and middle ear to direct sound to the inner ear through skull
vibrations
 Cochlea vibrates setting fluids into motion
 Hair cells activate sending signals to Auditory Nerve
 Auditory nerve fires, sending signals to the brain
TYPES OF HEARING LOSS
Conductive hearing loss
 Abnormal mechanical function
 Impaired air conduction with normal bone conduction
 Abnormal outer ear or middle ear with normal inner ear
Sensorineural hearing loss
 Abnormal sensory or neural function
 Impaired air and bone conduction
 Abnormal inner ear or auditory nerve with normal outer/middle ear function
Mixed Hearing Loss
 Combined conductive and sensorineural hearing loss
 Abnormality in outer/middle ear and inner ear