Overview
- An objective test used to assess middle ear function.
- Measures middle ear compliance with changing pressure in the External Auditory Canal (EAC).
Types of TympanogramZ
- Type A: Normal, inverted V near zero pressure.
- Type As: Reduced compliance pressure (otosclerosis).
- Type Ad: Increased compliance (ossicular discontinuity).
- Type B: Flat, indicating middle ear effusion or perforation.
- Type C: Maximum compliance beyond -100 mmH2O indicating Eustachian tube dysfunction.
Ear Canal Volume
- Measures the volume of the external ear canal.
- Volumes vary based on age.
- Type B with volumes >2.5 suggest perforation or patent ventilation tube.
- Type B with volumes <2.5 suggest Otitis Media with Effusion (OME).
Reading Tympanometry
- Types: A, B, C
- Normal External Auditory Volume: <2.5 ml
- Normal Middle Ear Compliance: 0.3-1.6
- Normal Range: -100 to +50 mmH2O
- Stapedial Reflex: Present or absent
