Abstract: A MEMS package comprises a first speaker arrangement configured for emitting sound in a first audio frequency range and a second speaker arrangement configured for emitting sound in a different second audio frequency range.

Abstract: A MEMS device includes a substrate having a cavity and a membrane structure mechanically connected to the substrate and configured for deflecting out-of-plane with regard to a substrate plane and with a frequency in an ultrasonic frequency range to cause a fluid motion of the fluid in the cavity. The MEMS device includes a valve structure sandwiching the cavity together with the membrane structure, wherein the valve structure includes a planar perforated structure and a shutter structure opposing the perforated structure and arranged movably in-plane and with a frequency in the ultrasonic frequency range and with regard to the substrate plane and between a first position and a second position. The shutter structure is arranged to provide a first fluidic resistance for the fluid in the first position and a second, higher fluidic resistance for the fluid in the second position.