White noise is broadly spread across the spectrum, low-frequency, midrange, and high-frequency sounds.
White noise has shown promising results related to memory, tinnitus, and concentration (among many other things).
Pink noise is louder at the low-frequency end of the spectrum, and softer at the high end.
Brown noise is even deeper, even stronger, at the low end and without the high-frequency sounds of white and pink noise. Moreover, pink noise and brown noise can improve people’s memory more than white noise.
If you have trouble falling asleep or are easily awakened during the night, many sleep specialists recommend trying a sound conditioner or noise machine. In the book “Say Good Night to Insomnia,” insomnia researcher Gregg Jacobs says these devices work in two ways: by blocking distracting noises and by producing soothing sounds that are relaxing and help to induce sleep.