Occlusion
The sensation from having a hearing aid or earmold in your ear, making it feel blocked up or like your voice is in a barrel is referred to as ‘occlusion-effect’. To get an idea of what occlusion is try to put a finger into each ear while talking or eating.
Oval window
The oval window is the junction between the middle ear and the inner ear. It contains the footplate of the stirrup, which act like a piston moving the fluids in the cochlea.