Purpose of the Visual Otoscopic Inspection?
NOT to diagnose a disorder, but to assess the outer ear and TM and middle ear for something obviously atypical
(can assist in interpreting other audiological evaluation results)
Obviously atypical things to look for in the Otoscopic Inspection
structural defect of the ear, head or neck
ear canal abnormalities
tympanic membrane abnormalities
Describing ear canal abnormalities for results of the Otoscopic Inspection
Blood or effusion (drainage)
excessive cerumen or foreign object
Describing tympanic membrane abnormalities for results of the Otoscopic Inspection
color: not normal if white or grey.
Bulging or Retraction
Fluid line or Bubbles
this term reflects what the test measures; combination of the words "impedance" and "admittance"
Tympanometry- 3 parts
peak admittance (sometimes static compliance)
physical volume (aka ear canal volume)
Acoustic Reflex Thresholds
measure stapedial muscle reflex, which stiffens the middle ear system when elicited by high intensity sounds.
Detecting middle ear disorders (tympanometry and reflexes)
Differentiating different types of middle-ear pathology (tymp. and reflexes)
Differentiating cochlear from retrocochlear pathology (reflexes & reflex decay)
Facial nerve (reflex) and eustachian tube function (tympanometry)
The Tympanic Membrane vibrates most easily when air pressure is...
equal on both sides (normal resting position), at 0 daPa
In tympanometry, the microphone can measure...
the probe tone is constantly on and the Microphone can measure how much sound is absorbed/admitted, and how much is reflected into the ear canal
In a normal middle ear, the greatest admittance is at ____, and declines as the air pressure
admittance (passing of acoustic energy) declines as the air pressure moves away from 0, either positively or negatively.
Tympanometry determines the...
admittance of sound into the middle ear at varying degrees of positive and negative pressure in the external auditory canal.
admittance of sound at the peak of the tympanometry trace.
in ml, cc or mmho
shown by the hight of the tympanogram at its peak
High peak admittance
greater than 2.0 ml.
-reflects flaccidity of TM/ossicles, aka excessive compliance
when there is negative peak pressure, this means...
middle ear pressure is negative relative to outer ear pressure. Sign of Eustachian Tube Dysfunction
Ear Canal Volume
provided on the screen or print out.
The Physical Volume of the ear canal beyond the probe
A too small Ear canal volume usually means...
there's an obstruction of the ear canal or improper probe placement
A too large ear canal volume usually means...
the tympanic membrane is not intact (so it picks up the volume of the middle ear too)
stiffened middle ear system.
normal shape, peak pressure, LOW peak admittance: < .3 ml
excessively middle ear system
normal shape, peak pressure, HIGH peak admittance: >2.5 ml
If a Type B tymp. has Normal physical volume...
TM is intact, there's no ear canal obstruction, but there's little to no mobility of the TM
A type B tymp with a physical volume that is too small means...
either the probe tip was misplaced, or there is an ear canal obstruction
Type C Tympanogram
normal shape, normal peak admittance, excessively negative peak pressure.
Type C Tymp. reflects...
eustachian tube dysfunction.
-may reflect oncoming of otitis media
Of the following, what pattern of
tympanometry results would you expect to be associated with a
conductive hearing loss related to a tympanic membrane perforation?
-Type A with abnormally large ear canal volume
-Type B with normal ear canal volume (not possible)
-Type B with abnormally large ear canal volume
Type B with abnormally large ear canal volume