Most people find two states as the most sleep-inducing—the presence of noise or absolute noiselessness. But there exists a grey area, which offers more colours for effective sleep.
In the pink of sleep
We’ll begin with pink noise, an ambient sound known to bring about restfulness. Think waves hitting the shore or rain falling on a wooden desk. To understand this better, let’s look at the principle on which sound waves function. A wave in sound is the varying degrees of disturbance in the movement of energy. These vibrations are present in the air, water and also the human brain. To create sound, these waves reverberate at a particular frequency.
“Even though most people harp on the merits of white noise, pink noise holds the secret to quality sleep. That’s because of the good balance of high and low frequencies contained within it. Its lower frequencies are deeper than white noise, therefore more calming,” says Gurugram-based audiologist Sachin Rathi. Pink noise slows down brain waves, stabilising sleep for longer periods. “Use it to make babies sleep,” says Rathi.
Pink noise is also one of the best frequencies for building memory and improving concentration. “Because memory develops in deeper states of sleep, slow sound waves are imperative,” says Rathi. These waves could be the ‘potential tool for enhancing memory in older populations and attenuating normal age-related memory decline,’ according to Dr Phyllis Zee, professor of neurology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine sleep specialist, who shared this insight as finding of a study on how slow-wave sleep is important for memory, especially in the older population.
Brown boost
Lower frequencies of sound are amplified in brown noise; even more than pink noise. Because the emphasis is more on base notes, brown noise helps build the architecture of sleep. It also helps ease a tired mind, making it most suitable for people who are prone to overthinking. “Brown noise such as the sound of strong winds, thunder, or a heavy downpour is recommended. This type of sound may also positively impact those with attention-deficit hyperactivity disorder,” says Rathi.
Out of the blue
“Blue noise may not work for everybody but is especially effective for those suffering from tinnitus (ringing noise in the ears) or other forms of ear fatigue,” says Rathi. Blue noise is a cluster of high-pitched sounds. Because the higher frequencies are amplified, it conceals background sounds well. Blue noise is not for you if you suffer from serious sleep or neurological conditions.
Blackout
This refers to a complete lack of noise. Also called dark noise, it is characterised by spurts of gentle rises in sound. For the most part, the other frequencies have no power. “The high notes hit you suddenly but not jarringly and with each note, one goes deeper into sleep,” says Delhi-based sleep specialist Roshini Sinha. Try a tape with the sporadic sound of a temple gong or a hiss of an animal.
Pink Noise
A good balance of high and low frequencies. The lower frequencies in pink noise are deeper than any other coloured noise, therefore most calming.
Listen to
✥ Waves hitting the shore
✥ Rain falling on a wooden desk
Benefits
✥ Stabilises sleep
✥ Improves concentration
Brown Noise
Lower frequencies of sound are amplified in brown noise. Because of this, it helps build proper sleep architecture of sleep, ie. the various stages of sleep.
Listen to
✥ Sound of strong wind
✥ Thunder
Benefits
✥ Soothes a tired mind
✥ May help reduce symptoms of attention-deficit/hyperactivity disorder
Blue Noise
Built on higher frequencies. Conceals background sounds well.
Listen to
✥ Ringing of bells
✥ Fireworks
Benefits
✥ Effective for those suffering from tinnitus (ringing noise in the ears) or other forms of ear fatigue
Black Noise
Complete lack of noise, with the exception of sudden spurts of sounds.
Listen to
✥ Temple gong
✥ Hiss of an animal
Benefits
✥ Helps you enter deeper sleep states much faster than other types of noise.