Abstract: Sound is recorded on color movie film using conventional techniques preferably by variations in density and printed in color such as cyan. Noise reduction on playback is achieved by utilizing a light source generating frequencies capable of being modulated by the color of the sound track and preferably high in infrared frequencies. The infrared frequencies do not see the color sound track but are responsive to noise and other impurities. The modulating signal will be affected by both the colored sound track and impurities. All light frequencies passing through the sound track are directed to a filter such as a dichroic cold mirror which passes the IR frequencies to a first detector and reflects the sound track modulated signal plus noise to a second detector. Apparatus is described for algebraically combining the output of both detectors to thereby cancel the effects of the noise signal from the desired sound track modulated signal.