Nyquist Frequency

Named after Harold Nyquist, the Nyquist frequency is the highest frequency that can be accurately represented by a digital sampling system. The Nyquist theorem demonstrated that the highest frequency that can be accurately represented by a digital sampling system is one half the frequency of sampling, i.e., one half the sampling rate. Thus, if a digitization system quantifies a signal (such as a sound wave) at a rate of 44,100 samples per second, it can only accurately capture frequencies up to 22,050 Hz.