A method and system for determining a persons heart pulse rate in noisy environments is provided. The method of determining a persons heart pulse rate includes radiating first and second wavelengths of light towards a tissue, measuring and storing a first and second set of parameter values from the signals reflected back from the first and second wavelengths respectively. The first set of parameter values represents a first signal corresponding to a combination of the heart pulse rate and extraneous noise and the second set of parameter values represents a second signal mainly comprising extraneous noise. The heart pulse rate is obtained by deducting the second set of parameter values from the first set of parameter values.
