Some say the most soothing of all noise frequencies, like rhythms cotton candy sleep washing through space.A deep rumble mixed with a stream of white combine for a perfect atmosphere. AmbientNoise.Online creates relaxing pink noise sounds to help mask the outside world. While sounds like city sounds and dogs barking will stimulate your brain, other sounds like pink noise will help relax your brain to get better sleep. Pink noise is actually deeper in sound than white noise and has a bass rumble kind of sound.