A measurement amplifying circuit (400) for a piezo-electric sensor (100) positioned in an internal combustion engine supplying a signal to be measured, includes: a module (420) for generating a common mode voltage; a differential amplifier (410); and a subtraction module (430). The module (420) for generating a common mode voltage is to be connected to a wall (111) of the engine, the module (420) for generating a common mode voltage being suitable for supplying a common mode voltage signal (Vcm) reproducing the variations of an engine signal (Sb) received from the wall (111) of the engine.