Most systems contain rotating machinery, which cause vibration and hence noise. In order to reduce the noise of the systems, noise control is used. When passive measures are at their limits, active system can be used to further improve the noise reduction. Inertial mass actuators are suited for this task because they can be directly mounted onto the system and do not require any additional support. The actuator can induce forces into the system and reduce the vibration and noise by means of active structural acoustic control. However, the inertial mass actuator radiates unwanted noise. In order to achieve an audible noise reduction with the inertial mass actuator, it is required that the emission of actuator is respectively lower than the one of the target system. In this paper an analysis of the noise emission of an piezo inertial mass actuator is carried out. The sound power level and the directivity of the actuator are measured in a half-anechoic chamber. In addition, different housings for the actuator with and without foam are tested and compared in order to reduce the noise passively. The noise level of the actuator will then be compared to the noise level of a planetary gearbox test rig without active noise control to determine the influence of the inertial mass actuator on the overall sound pressure level.