Anti-noise loudspeaker combating noise for direct use in MR tomography esp. control of sound in brain and heart studies

摘要

The anti-noise loudspeaker for actively combatting noise, esp. for direct use in magnetic resonance tomographs, without interfering with the image production. An electrodynamic low middle tone loudspeaker without its own magnets is provided. With the use of this loudspeaker for anti-noise production, the drive power of the moving coil of the antimagnetic loudspeaker, is producible by an inhomogeneous magnetic field spatially spread in the direction of the moving coil main axis.