Sound transmission to inner earSound transmission to inner ear Impedance mismatch between air in middle ear and Impedance mismatch between air in middle ear and

fluid in inner earfluid in inner ear

To compensate:To compensate:

Area difference between TM and footplate of the stapes (55/3.2 Area difference between TM and footplate of the stapes (55/3.2 = 17)= 17)

Ossicular lever action (1.3/1 = 1.3)Ossicular lever action (1.3/1 = 1.3)

Buckling movement of TM (2/1 = 2)Buckling movement of TM (2/1 = 2)

Total pressure increase = 17 * 1.3 * 2 = 44.2 Total pressure increase = 17 * 1.3 * 2 = 44.2

Total dB increase = 33 dBTotal dB increase = 33 dB