According to an embodiment, a method of operating a speaker with an acoustic pump includes generating a carrier signal having a first frequency by exciting the acoustic pump at the first frequency and generating an acoustic signal having a second frequency by adjusting the carrier signal. In such embodiments, the first frequency is outside an audible frequency range and the second frequency is inside the audible frequency range. Adjusting the carrier signal includes performing adjustments to the carrier signal at the second frequency. Other embodiments include corresponding systems and apparatus, each configured to perform corresponding embodiment methods.