A system is provided for isolating a hidden waveform representing hidden information from a composite waveform. The system comprises a processor a memory configured to store instructions executable by the processor and a comparator. The instructions cause the processor to estimate that portion of a received composite waveform that represents a first signal source and generate a waveform that represents an estimated first signal source. The comparator comprises a first input coupled to receive the composite waveform and a second input coupled to receive the generated waveform from the processor. The comparator is configured to subtract the generated waveform from the composite waveform and output a resulting estimated hidden waveform, representing the hidden information.
