Abstract: Techniques described herein generally relate to generating an audio signal with a speaker. In some examples, a speaker device includes an acoustic medium; and at least one ultrasound source coupled to the acoustic medium through at least one time-varying acoustic coupler. The acoustic coupler is configured to be electrically activated to operate at its mechanical resonance so as to generate an audio signal.
Abstract: Techniques described herein generally relate to generating an audio signal with a speaker. In some examples, a speaker device is described that includes a membrane, an acoustic cavity and an acoustic channel. The membrane can be configured to oscillate along a first directional path and to generate an acoustic signal. The acoustic signal traverses the acoustic channel and generates an audio signal.