hearing and balance Flashcards
outer ear
Gathers sound and allow it to pass through the air canal to the eardrum
middle ear
Amplify the sound
inner ear
Translate sound into vibration into electrical signals
conductive hearing loss (CHL)
Pathology of the outer and/or middle ear which causes a loss in the conduction of the sound through the system.
Most can be medically treated
what conditions are associated with CHL?
Ear infection (otitis media)
Perforated eardrum
Benign tumors
Otosclerosis: abnormal growth of bone in the ears
Impacted earwax (cerumen)
Infection in the ear canal (external otitis)
Presence of a foreign body
Absence or malformation of the outer ear, ear canal, or middle ear
Sensorineural (SNHL)
Damage to the sensory cells in the cochlea or along the auditory neural pathway.
Conditions associated with SNHL:
Noise induced hearing loss
Ototoxicity: toxic to the ear – generally medication side effects
Meniere’s disease- inner ear disorder that impacts balance and hearing
Acoustic Neuroma/Vestibular Schwannoma - tumors
Presbycusis: most common type caused by natural aging
Viral
Meniere’s Disease
Sensorineural disorder of the inner ear Cause unknown Suspected cause is fluid in the tubes of the inner ear, autoimmune disease, allergies, genetics Symptoms include episodes of: Dizziness Vertigo (sensation of spinning) Ringing sound (tinnitus) Hearing Problems Feeling of fullness Usually only in one ear
Prebycusis
Sensorineural disorder of the inner ear or blood supply
Age related gradual hearing loss in both ears
1/3 adults
People not always aware
Symptoms:
Speech sounds mumbled
Tinnitus
Deep voice easier to hear
Most often affects ability to hear high-pitched noises (“s” and “th”)
Causes:
Most likely due to a loss of hair cells
Can be due to changes in blood supply to the ear
mixed hearing loss
A combination of sensorimotor hearing loss (SNHL) and conductive hearing loss (CHL)
For example: A client has an ear infection causing a CHL and has age related SNHL
otoscopy
Visual inspection of outer ear
- Pinna
- External auditory meatus (ear canal)
- Tympanic membrane (eardrum)
immitance testing
Localizes the part of the ear involved in hearing loss
Probe put into the middle ear
Tympanometry
Acoustic reflex thresholds
Acoustic reflex thresholds
Measures the contraction of the stapedius muscle in response to a loud sound
Helps with site of lesion; various patterns
tympanometry
Diagnoses conductive issues
Not a hearing test
Pressure is placed on the eardrum
Measure the movement of the eardrum at various pressures
At what pressure does the sound go through to from the outer to the middle ear
tympanometry
By understanding how much sound is reflected back during this test we can tell how much energy can transmit through the middle ear
Results: Scarring in the middle ear Earwax Lack of mobility of the ossicles Fluid in the middle ear Perforation of the eardrum
