Noun
The fluid which surrounds the membranous labyrinth of the internal ear, and separates it from the walls of the chambers in which the labyrinth lies.
Source: Webster's dictionaryThe middle ear thus serves to convert the energy from sound pressure waves to a force upon the perilymph of the inner ear. Source: Internet
When the stapes presses on the oval window, it causes the perilymph, the liquid of the inner ear to move. Source: Internet
There is a layer of perilymph fluid between them. Source: Internet