Why pink noise is best for enhancing sleep and memory: system-based explanation

Several researchers found out that acoustic stimulation during sleep enhances sleep and enhances memory. An interesting – and somewhat mysterious – part of this phenomenon is that out of all possible types of noise, the pink noise leads to the most efficient stimulation. In this paper, we use general system-based ideas to explain why in this phenomenon, pink noise works best. 1 Formulation of the Problem Acoustic stimulation helps sleep and memory: a brief description of the observed phenomenon. Several researchers found out that acoustic stimulation during sleep help patients to sleep better and enhanced their memory; see, e.g., [4, 5, 6, 8]. Qualitative explanation of the phenomenon. While the level of enhancement was much higher than most researchers expected, the very fact that exercising some organ is good should be expected: it helps to exercise muscles, it helps to exercise brain activities, it helps to exercise visual activities, etc. It is also understandable that a noise helps better than a signal emitted at a single frequency: just like exercising different muscles is better for a person’s overall health than focusing on a single group of muscles, just like practicing different types of mental activities is better for a person’s mental abilities than repeatedly performing tasks of the same type, it is reasonable to expect that processing components of different frequencies will work better than processing only one frequency.