Pink noise is a type of sound that contains equal energy across octaves, making it sound balanced to the human ear. Unlike white noise, which has a higher concentration of high frequencies, pink noise has more low-frequency sounds, creating a deeper and softer sound profile. This characteristic makes it soothing and often used for relaxation or sleep. Many people use pink noise to help mask background sounds, making it easier to concentrate or fall asleep. It is commonly found in nature, such as the sound of rain or ocean waves, and is also used in audio engineering to test sound systems and acoustics.