A heart rate monitoring method and device to analyze signals in time or frequency domain with motion noise signal reduction comprises at least two LEDs for providing two different light signals for incidenting into a portion of a human, a photodetector for detecting two reflected and scattered signals reflected and scattered form the human, and a processor for eliminating motion noise signal cause by any motion of the human. The processor may compare the two reflected and scattered signals and execute an independent component analysis to obtain a correct heart rate signal in time domain, and then the processor can calculate the correct heart rate. The processor may transform the two reflected and scattered signals form time domain to frequency domain and compare the two reflected and scattered signals in frequency domain to obtain a heart rate signal in frequency domain, and then the processor can calculate the heart rate.
