The Art of Tranquility is your best online source for acoustic environments to help with sleep, focus, study, and concentration.Noise can interrupt sleep, and interrupted sleep is less restorative. Undesirable noise, like air and vehicle traffic that doesn’t disturb sleep can still affect sleep by changing the time we spend in different sleep stages, increasing lighter sleep stages and decreasing more restorative slow wave and REM sleep. Noises during sleep may increase secretion of hormones such as adrenaline and cortisol and elevate heart rate and blood...