A system and method of filtering input data to remove power lineinterference is disclosed. The system and method estimates the statistics oftheinput signal and include determining a value (R) from the ratio of a peakamplitude(A peak) and a root-mean-square of the amplitudes of the interferenceharmonics(A rms), calculate a running histogram of the determined value (R) todetermine athreshold value (TH R), comparing the determined value (R) to the determinedthreshold value (TH R) to make a decision about feature existence, andoutputting afeature decision. The system and method include estimating the interferencelevelto determine if interference is low level or high level. The system and methodinclude estimating interference using the feature detection, amplitude andphase；and removing the estimated interference from the signal to result in a signalsubstantially free of power line interference.
