What is tympanometry?
Impedance testing
• Not a test of hearing; a test of middle ear function
Why perform tympanometry?
- The movement of the TM is measured
- Results indicate the status of the middle ear and outer ear
- Components: physical volume, compliance (how much can TM move?)
Components of tympanometry:
- Physical Volume: the amount of air measured in the space between the probe tip of the tympanometer and the TM
- Compliance (Mobility): In a normal middle ear system the TM and attached ossicular chain vibrate easily, allowing the transmission of sound energy to the inner ear
What’s a normal ear canal volume?
•0.3 to 0.9 ml is normal in children
•0.6 to 2.0 ml is normal in adults
(below)2.0 ml is abnormally large= patent PE tube or perforation
What does ECV stand for?
Ear Canal Volume
What is daPa?
Depapascal or a unit of measure for pressure at the pick (maximum pressure in the ear)
1 daPa equal 1-PA and is approximately the pressure of a column of water 1mm high.
What are the normative values for daPa?
-150 → +50
Results of tympanometry have names and shapes what are they?
- Normal – Type A
- Middle Ear Fluid –Type B
- Poorly functioning Eustacian Tube – Type C
- Scarred TM – Type As
- Broken Ossicles – Type Ad
- Fixed Ossicles (otosclerosis) – Type As
- TM Perforation/Patent (open) PE Tubes – Type B with large volume
Referral Criteria is what?
- Refer- Type B; unless PE tube, otorreha, otalgia
* Replicate and be sure to print the results so we have record of what it looked like
What is otorreha
Effusion
What is otalgia
Searing pain→ warm compress helps
Instrumentation
- Sound source
- Air pump
- Analysis section
- Acoustic reflex stimulus
DO NOT
perform on children less than 6 months of age because their ossification is incomplete, unless you use the appropriate probe tone
What is static compliance
Mobility of TM → on print out =PEAK
- 2 to 1.8 ml is normal
- 8 is abnormally high =hyperflaccid TM and a disarticulation of the ossicular chain
