Green noise is a type of noise that has an equal loudness per octave, meaning that each octave of sound has the same perceived loudness by the human ear. This is achieved by boosting the low frequencies and reducing the high frequencies. As a result, green noise has a balanced and natural sound that is pleasant to listen to. Green noise is not a widely recognized term in the field of acoustics or sound engineering, unlike pink noise and brown noise. However, it is sometimes used in sound therapy, relaxation, and meditation. Some people find that listening to green noise can promote relaxation, reduce stress, and improve focus. Green noise may be used as a background sound for studying, working, or sleeping, as it can help mask other distracting sounds in the environment. However, more research is needed to determine the specific effects of green noise on human physiology and psychology.