An electric vehicle vacuum pump assembly includes a combination, a separate acoustic barrier casing configured to encase the combination in each of a radially-spaced relationship and an axially-spaced relationship, and an annular gastight attenuation assembly radially arranged between the separate acoustic barrier casing on a first side and the combination on a second side. The combination comprises a pump unit and a drive motor comprising a rotor space, a stator space, a ventilation inlet, and a ventilation outlet. The rotor space comprises a motor rotor, and the stator space comprises a motor stator. The separate acoustic barrier casing comprises an intake connection and a discharge connection. The ventilation inlet and the ventilation outlet of the drive motor are configured to provide a forced ventilation past the annular gastight attenuation assembly and through at least one of the rotor space and the stator space.