Noise reduction method for recorded signals

Claim 1

IN COMBINATION FOR IMPROVING THE SIGNAL-TO-NOISE RATIO OF A BAND OF INPUT SIGNALS WHERE NOISE OCCURS PRIMARILY IN A FIRST PARTICULAR RANGE OF BAND, A FIRST FILTER RESPONSIVE TO SAID SIGNALS IN SAID BAND OF INPUT SIGNALS TO PROVIDE A DELAY FOR SAID SIGNALS IN SAID BAND AND TO PASS ONLY THE SIGNALS IN A SECOND PARTICULAR RANGE FORMING SAID BAND OF SIGNALS WITH SAID SIGNALS IN SAID FIRST PARTICULAR RANGE, A FIRST DELAY LINE RESPONSIVE TO SAID SIGNALS IN SAID BAND TO PROVIDE A DELAY IN SAID SIGNALS IN SAID BAND CORRESPONDING TO THE DELAY PROVIDED BY SAID FIRST FILTER, A FIRST DIFFERENTIAL AMPLIFIER RESPONSIVE TO SAID SIGNALS IN SAID BAND FROM SAID FIRST DELAY LINE AND RESPONSIVE TO SAID SIGNALS IN SAID SECOND PARTICULAR RANGE FROM SAID FIRST FILTER FOR COMBINING SAID SIGNALS TO PASS ONLY SAID SIGNALS IN SAID FIRST PARTICULAR RANGE OF SAID BAND, A FIRST LINEAR AMPLIFIER RESPONSIVE TO SAID SIGNALS IN SAID SECOND PARTICULAR RANGE OF SAID BAND TO LINEARLY AMPLIFY SAID SIGNALS, A FIRST NON-LINEAR AMPLIFIER RESPONSIVE TO SAID SIGNALS IN SAID FIRST PARTICULAR RANGE OF SAID BAND FROM SAID DIFFERENTIAL AMPLIFIER TO PRODUCE SIGNALS HAVING AN OUTPUT WITH AN AMPLITUDE WHICH CONSTITUTES A FRACTIONAL POWER LESS THAN UNITY OF THE AMPLITUDE OF SAID SIGNALS INTRODUCED TO SAID NON-LINEAR AMPLIFIER IN SAID FIRST PARTICULAR RANGE OF SAID BAND, A FIRST ADD CIRCUIT RESPONSIVE TO SAID SIGNALS IN SAID SECOND PARTICULAR RANGE FROM SAID FORST LINEAR AMPLIFIER AND RESPONSIVE TO SAID SIGNALS IN SAID FIRST PARTICULAR RANGE FROM SAID FIRST NONLINEAR AMPLIFIER TO COMBINE SAID SIGNALS, MEANS RESPONSIVE TO SAID SIGNALS FROM SAID FIRST ADD CIRCUIT TO PROVIDE A TRANSDUCING ACTION ON SAID SIGNALS, A SECOND FILTER RESPONSIVE TO SAID SIGNALS PRODUCED BY SAID TRANSDUCING MEANS TO PROVIDE A DELAY IN SAID TRANSDUCED SIGNALS AND TO PASS ONLY THE SIGNALS IN SAID SECOND PARTICULAR RANGE OF SAID TRANSDUCED SIGNALS, A SECOND DELAY LINE RESPONSIVE TO SAID SIGNALS PRODUCED BY SAID TRANSDUCING MEANS TO PROVIDE A DELAY IN SAID TRANSDUCED SIGNALS CORRESPONDING TO THE DELAY PROVIDED BY SAID SECOND FILTER, A SECOND DIFFERENTIAL AMPLIFIER RESPONSIVE TO SAID DELAYED SIGNALS FROM SAID SECOND DELAY LINE AND TO SAID SIGNALS PASSED BY SAID SECOND FILTER IN SAID SECOND PARTICULAR RANGE FOR COMBINING SAID SIGNALS TO PASS ONLY SAID SIGNALS IN SAID FIRST PARTICULAR RANGE OF SAID BAND, A SECOND LINEAR AMPLIFIER RESPONSIVE TO SAID SIGNALS IN SAID SECOND PARTICULAR RANGE FROM SAID SECOND FILTER FOR LINEARLY AMPLIFYING SAID SIGNALS, A SECOND NON-LINEAR AMPLIFIERRESPONSIVE TO SAID SIGNALS IN SAID FIRST PARTICULAR RANGE FROM SAID SECOND DIFFERENTIAL AMPLIFIER FOR AMPLIFYING THE AMPLITUDE OF SAID SIGNALS BY A PARTICULAR POWER GREATER THAN UNITY OF INVERSELY RELATED TO SAID PARTICULAR FRACTIONAL POWER, AND A SECOND ADD CIRCUIT RESPONSIVE TO SAID SIGNALS IN SAID SECOND PARTICULAR RANGE FROM SAID SECOND LINEAR AMPLIFIER AND RESPONSIVE TO SAID SIGNALS IN SAID FIRST PARTICULAR RANGE FROM SAID SECOND NON-LINEAR AMPLIFIER TO COMBINE SAID SIGNALS FOR THE PRODUCTION OF OUTPUT SIGNALS HAVING CHARACTERISTICS CORRESPONDING TO SAID INPUT SIGNALS.