Impedance Audiometric response in serous otitis media:-

Types of tympanograms Type A Normal tympanograms Type As Compliance is lower at or near ambient air pressure.It is seen in fixation of ossicles,malleus fixation. otosclerosis Type Ad High compliance at or near ambient pressure.It is seen in ossicular discontinuity or thin and lax tympanic membrane. Type B Flat or dome shaped graph. No change in compliance with pressure changes.It is seen in middle ear fluid or thick tympanic membrane. Eg - serous otitis media Type C maximum compliance occurs with negative pressure in excess of 100 mm H20.It is seen in retracted tympanic membrane and may show some fluid in middle ear. Eg ET obstruction.