Patent ID: 7986795

Claim:
A media playback apparatus for protecting media content against unauthorized duplication at the output stage during media playback comprising: a digital signal source for providing an electrical signal representing undistorted media content; a processing unit for processing the signal from said signal source; a distorting unit for introducing non-linear distortion to the signal from said processing unit and outputting a distorted analog electrical signal such that the distorted analog electrical signal is perceived by a user as distorted on listening, wherein said non-linear distortion cures at least a non-linear distortion inherent to an electroacoustic transducer; the electroacoustic transducer for converting the distorted analog electrical signal from said distorting unit to undistorted energy representing said undistorted media content; and an electrical connection link for electrically transmitting the distorted analog electrical signal from said distorting unit to said electroacoustic transducer.