While we call it “white noise” because that’s the term used by most of our customers, our Dohm products are actually creating "pink noise." If you sample various "colors" of sounds, you will quickly hear that actual "white noise" is highly annoying and not conducive to sleep. Our Marpac Signature Sound contains less high frequency content than “true” (“scientifically defined”) white noise, and also less than most competing sound machine models on the market. The ear is more sensitive to high frequency sounds, so it perceives our sound as more soothing.