Leistner, PhilipPhilipLeistnerBay, KarlheinzKarlheinzBayLeistner, MichaelMichaelLeistnerMaysenhölder, WaldemarWaldemarMaysenhölder2022-03-082022-03-082014https://publica.fraunhofer.de/handle/publica/310398Source: WO14195494A1 [EN] The invention relates to a sound transducer having a housing (3), which housing encloses a volume (4) and at least one surface or partial surface of which is made of a flat structure (1) mounted so as to be capable of vibration, wherein a drive unit (2) is provided for the flat structure mounted so as to be capable of vibration and wherein the volume (4) can be evacuated. The sound transducer is characterised in that the flat structure (1) mounted so as to be capable of vibration is designed as part of a spring arrangement, wherein the spring arrangement is in an untensioned, or barely tensioned state when ambient pressure or near ambient pressure prevails in the volume, has adequately high spring stiffness to withstand the pressure difference arising when the housing (3) is evacuated and has a lower spring stiffness when the housing (3) is evacuated, such that the flat structure (1) mounted so as to be capable of vibration can be excited into vibration with little force.de690patent102013210708