A MEMS speaker that may include a membrane positioned in a first plane, wherein the membrane may be configured to oscillate at a first frequency thereby generating an ultrasonic acoustic signal; and an acoustic modulator that may include a blind and a shutter; wherein the blind may be positioned in a second plane; wherein the shutter may be positioned in a third plane; wherein the first plane, the second plane and the third plane may be substantially separated from each other; and wherein the acoustic modulator may be configured to (a) receive or generate a shutter control signal and a blind control signal, and (b) modulate, in response to the shutter control signal and the blind control signal, the ultrasonic acoustic signal such that an audio signal may be generated.