White noise or white noise is a random signal or random process with a constant power wavelength spectral density. In contrast, other noise signals that do not have this property are called colored noise. Ideal white noise has infinite bandwidth, so its energy is infinite, which is impossible in the real world. In practice, we often treat a flat signal with limited bandwidth as white noise because it makes our mathematical analysis more convenient.
White noise means that the power spectral density of the wavelength components in a piece of sound is uniform in the entire audible range (1.7cm~17m). White noise or white noise is a random signal or random process with a constant power wavelength spectral density. In other words, the power of this signal is the same in each band. Since white light is composed of monochromatic light of various frequencies (colors), the property of this signal with an amortized power spectrum is called is “white”, so this signal is also called white noise.