Patent ID: 8139794

Claim:
A speaker device, comprising: a substrate; a membrane above the substrate, the membrane and the substrate having a second chamber enclosed between the membrane and the substrate; an electrode above the membrane, the electrode having a plurality of holes, the electrode and the membrane having a first chamber enclosed between the electrode and the membrane; a frame coupled with the substrate, the membrane, and the electrode to form a stacked structure having the first chamber between the electrode and the membrane and having the second chamber between the substrate and the membrane; a plurality of first supporting members in the first chamber space and being coupled between the electrode and the membrane, the plurality of first supporting members spacing the membrane apart from the electrode; and a plurality of second supporting members in the second chamber space and being coupled between the membrane and the substrate, the plurality of second supporting members spacing the membrane apart from the substrate; wherein the membrane comprises an electret layer and a conductive electrode layer; at least some of the first and second supporting members have height variations from others; and at least one of the first and second supporting members is made of a flexible material.