MEMS loudspeaker for generating sound waves in the audible wavelength spectrum, with a support element, a membrane deflectable with respect to the support element along a z-axis, at least one piezoelectric actuator supported on the support element for deflecting the membrane, designed as a cantilever arm and having a fixedly clamped end and a freely oscillating free end, a stroke structure via which the actuator is connected to the membrane, an electronic control unit for driving the actuator, at least one piezoelectric position sensor, which is integrated into the cantilever arm and by means of which the control unit can be provided a sensor signal that is dependent on the membrane deflection,and an elastic connecting element which connects a free end of the position sensor, which is integrated in the actuator designed as a cantilever arm, to the stroke structure; wherein the control unit is designed in such a manner that the control unit performs a functional self-test process automatically, during the functional self-test process, the control unit controls the actuator with a reference actuator signal, with which the control unit compares a sensor signal with a reference signal stored in the control unit to obtain a comparison result, in which the control unit detects differences in the behavior of the MEMS loudspeaker by comparing the sensor signal with the reference signal when a deviation is detected, namely a reduction in performance due to aging or external influences, and in which the control unit, by taking into account the comparison result, henceforth operates and controls the actuator in a controlled manner with a higher electrical voltage compensating the reduction in performance when a reduction in performance is detected. with a support element, a membrane deflectable with respect to the support element along a z-axis, at least one piezoelectric actuator supported on the support element for deflecting the membrane, designed as a cantilever arm and having a fixedly clamped end and a freely oscillating free end, a stroke structure via which the actuator is connected to the membrane, an electronic control unit for driving the actuator, at least one piezoelectric position sensor, which is integrated into the cantilever arm and by means of which the control unit can be provided a sensor signal that is dependent on the membrane deflection,and an elastic connecting element which connects a free end of the position sensor, which is integrated in the actuator designed as a cantilever arm, to the stroke structure; wherein the control unit is designed in such a manner that the control unit performs a functional self-test process automatically, during the functional self-test process, the control unit controls the actuator with a reference actuator signal, with which the control unit compares a sensor signal with a reference signal stored in the control unit to obtain a comparison result, in which the control unit detects differences in the behavior of the MEMS loudspeaker by comparing the sensor signal with the reference signal when a deviation is detected, namely a reduction in performance due to aging or external influences, and in which the control unit, by taking into account the comparison result, henceforth operates and controls the actuator in a controlled manner with a higher electrical voltage compensating the reduction in performance when a reduction in performance is detected.