Thousands of people listen to coloured sounds on platforms like YouTube and through meditation apps. White noise, a sound that can drown out background noise and increase sleep quality, has gained popularity in recent years as many people seek improved rest and focus. There's now growing interest in other coloured noises such as pink, brown and green noises.
Scientists say sound consists of waves, similar to light. It can be described using colours based on the distribution of its frequencies just like light appears red at lower wavelengths, while it is more blue and violet at higher wavelengths. Thousands of people listen to these sounds on platforms like YouTube and through meditation apps.
"Many people are looking for how to use sounds to improve their sleep. Most of these applications and programs and devices use continuous sounds, which are helpful to mask external noises and allow people to sleep better by not being disturbed by other sounds around them," said Dr Roneil Malkani, an associate professor of neurology in the sleep medicine division at Northwestern University in the US. With potential benefits for sleep, concentration and relaxation, the coloured noises provide different auditory experiences.
While white noise is often described as a static-like sound, brown noise has deeper rumbling tones. Green noise sits between white and brown noise in frequency. In 2019, researchers at Northwestern University looked into whether pink noise can help enhance sleep and mem.
