Anatomy
What comprises the Outer Ear?
Pinna & External Auditory Canal
What is Phase Locking
when a singular fiber is firing at the same point during a phase of a sound wave.
What is Otitis Media & what tympanogram goes with it
Inflammation and infection of the ear from Effusion. Happens more often in kids, and occurs with Tympanogram B and C
What is conductive hearing loss
What ways do you remove cerumen and don't remove cerumen
Do: use mechanical tools such as loops or curettes, do buy OTC drugs, lubrication for dry ear wax or vacuum suction
DO NOT: use Q-tips (perforate TM or cerumen impactation) and Ear Candling
What is the function of the Outer Ear
To amplify sounds from the free field to the tympanic membrane and to help in localization (binaural & interaural)
What is the Volley Principle
When a soundwave is moving too fast (rate saturation), so several different neurons fire at a specific point, to convey the frequency of the wave.
What is Otosclerosis and what is it's cure and it's tympanogram
Building up bone around the ossicles particularly the Stapes
Can be fixed with a Stapedectomy
tympanogram A (s)
What is Presbycusis Sensory Hearing Loss
Death of Hair cells, hearing is less clear.
low frequency hearing loss
What is Impedance
Resistance to movement, is affected by mass and stiffness.
What is the correct order of the Ossicles
Malleus, Incus, Stapes
What is two-tone suppression?
When a second noise is added above or below the characteristic frequency, therefore dimming the clarity of the characteristic frequency
What is Ossicular Discontinuation and it's tympanogram
When the ossicular chain is disconnected, it is caused by temporal bone fracture, tympanic membrane perforation from trauma, chronic otitis Media or Choleatetomas.
Type A (d)
What is Neural Presbycusis Hearing Loss
loss of auditory nerve cells
start with 35,500 lose 2,100 per decade.
low frequency hearing loss
What are two ways to test immittance
MEMR & tympanometry
What are the three canals found in the Cochlea
Vestibular Canal (connects to the oval window)
Middle Canal (Scala Media)
Tympanic Canal (connects to the round window)
What are the factors of Impedance
Stiffness (affects low frequency)
Mass (affects high frequency)
What is the role of the Stapedius Muscle
to prevent loud noises from harming the inner ear. Prevents low frequencies from passing through
Slow (10 - 150 ms), but can be activated prior to self talk
What is Mechanical/Cochlear Conductive Hearing Loss
thickening/stiffening of the basilar membrane
Low frequency hearing loss
what are the uses of clinical immittance tests
to differentiate between middle ear diagnosis (tympanometry)
to differentiate between cochlear or retrocochlear diagnosis (MEMR)
What are some of the differences between Inner and Outer Hair Cells
Inner Hair cells are Afferent Neurons, they are shorter therefore moved by endolymph, and they tell us when a sound is present.
Outer Hair Cells are efferent neurons, they are longer therefore moved by the tectorial membrane and they allow us to interpret what the sound is saying (clarity)
What does the Equal Loudness Contour show
Not all frequencies are heard at the same loudness. (low frequencies are quieter, higher frequencies are louder)
Why do kids get ear infections more often than adults?
what is Metabolic Presbycusis
deteriorating of the stria vascularis
unable to produce endolymph for the hair cells so they don't function as well
What is Right ipsilateral, right contralateral, left ipsilateral, left contralateral and what test do they belong to
MEMR
RI: probe right, measure right
RC: probe right, measure left
LI: Probe left, measure Left
LC: probe left, measure right