Structures & Functions of the Ear/Types of Hearing Loss Flashcards
made of cartilage
collect sound and direct to ear canal
helps w/ localization
protects the middle ear components
amplifies high frequencies
pinna or auricle
contains cerumen (wax) glands
funnels sound to the tympanic membrane
external auditory canal (EAC)
separate outer ear from middle ear
vibrates in response to acoustic energy
where acoustic energy is changed into mechanical energy
tympanic membrane (ear drum)
small, air-filled space within the temporal bone
lined w/ mucous membrane
move mechanical energy to the inner ear
middle ear
auditory ossicles (ossicular chain)
malleus (hammer)
incus (anvil)
stapes
first bone in the chain
attached to the tympanic membrane
malleus (hammer)
middle bone
incus (anvil)
last bone
attached to the oval window
stapes
separates the middle ear from the inner ear
oval window
pressure relief port
round window
equalizes pressure between the middle ear with the nasopharynx
Eustachian tube (ET)
consists of the cochlea and semi-circular canal
fluid filled space in the temporal bone
contains organ for hearing and balance
inner ear
snail-like, fluid filled structure
disrupts the basilar membrane, which serves as a base for the organ of Corti (contains hair cell)
cochlea
high pitch
= base of cochlea
low pitch
= spec of cochlea
regulates balance
within the inner ear
shares fluid with cochlea
consists of three semi-circular canals
vestibular system
carries signals for hearing and balance from the inner ear through the brain stem to the brain
auditory/acoustic nerve (CN VIII)
energy transmission flow
acoustic–mechanical–hydraulic (mechanical)–electrical
when the pathway of sound is blocked in the outer ear or middle ear
conductive hearing loss (CHL)
symptoms of CHL
speak softer
body/head noises are more noticeable
pressure in the ear
CHL in the external ear
cerumen impaction
foreign body
deformities
collapsed ear canal
CHL in the middle ear
middle ear infection (otitis media)
ruptured ear drums
otosclerosis
treatment of CHL
temporary will resolved on its own
cleansing, medicine, or surgery
typically permanent and untreatable
sensorineural hearing loss (SNHL)
symptoms of SNHL
speak louder
difficulty understanding speech
tinnitus
loss in high frequencies
causes of SNHL
congenital, genetic, prenatal influence
ototoxic medicine
trauma to the head
illnesses
aging process (presbycusis)
acoustic neuromas (tumors)
most frequent form of SNHL that an OHC will encounter
damages hair cells as a result of prolonged exposure
noise induced hearing loss (NIHL)
noise notch
3-6k Hz
most commonly located at 4k Hz
treatment of SNHL
hearing aids
cochlear implants
a person has a combination of conductive (outer/middle ear) and sensorineural hearing loss
mixed loss
interference with the pathways from the brainstem to the auditory cortex
central hearing loss
no medical or physical reason for the loss
conscious exaggeration
non-organic hearing loss
(pseudohypacusis/functional hearing loss)
symptoms of non-organic hearing loss
booth loss
symmetrical hearing loss
no response to pure tones
restlessness
pressing on earphones
flinching
purpose of lighted ear inspection (LEI)
rule out abnormalities
expedite care if needed
when to inspect ears
prior to hearing test
when fitting HPDs
equipment required for LEI
otoscope
canal is open
TM/malleus is visible
normal findings
TM not visible
infection
drainage
blood in canal
do not attempt hearing test
foreign body
drainage/blood
cerumen blocking >25% of TM
deformities blocking >25% of TM
do not attempt HPD fitting
