Pink & White Noise
Pink noise or 1/ƒ noise is a signal or process with a frequency spectrum such that the power spectral density (energy or power per Hz) is inversely proportional to the frequency. In pink noise, each octave carries an equal amount of noise power.
Pink noise is similar to white noise, it also contains the wide range frequency signal in the spectrum. It is commonly found in nature environment. Unlike white noise, listening pink noise is more comfortable. The sound is quite similar to ocean. Some people play it in the office for relaxation and concentration.
Pink noise is a variant of white noise. Pink noise is white noise that has been filtered to reduce the volume at each octave. This is done to compensate for the increase in the number of frequencies per octave. Each octave is reduced by 6 decibels, resulting in a noise sound wave that has equal energy at every octave.
Pink noise is signal present on the frequency scale which helps in reducing the background noises. It is called Pink noise because it is placed in between the white and the red noise on the scale of frequency spectrum. Physicists also express this noise as the1/f noise or even flicker noise and is found to have equal force of energy in almost all the octaves. We as humans do not have the power to perceive all the existing frequencies with the same intensity. For us, the frequencies which lie between the ranges of 2 to 4 kHz can be a loud sound. When we hear such loud noise, we cannot interpret the other sound frequencies clearly.
Pink noises have been found to be present in various other systems naturally. According to the astronomers, the electromagnetic radiations from outer space have shown the presence of pink noise in the radiations which are emitted by particular stars. Almost all the electronic equipments and gadgets have been found to generate this noise as it is found in carbon composite resistors. Herein it is known by the name of flicker noise. Even in the biological field, the heart beat or the DNA sequence statistics have been found to produce pink noise.
White noise is the randomly generated noise signal. The signal has equal power in all frequency. Some people suggested that it is good to use white noise for burn-in, because of its fair distribution of each sound frequency, from treble to bass. Aside from headphone burn-in, some people use it to help baby sleep easier.
White noise is a sound that contains every frequency within the range of human hearing (generally from 20 hertz to 20 kHz) in equal amounts. Most people perceive this sound as having more high-frequency content than low, but this is not the case. This perception occurs because each successive octave has twice as many frequencies as the one preceding it. For example, from 100 Hz to 200 Hz, there are one hundred discrete frequencies. In the next octave (from 200 Hz to 400 Hz), there are two hundred frequencies.