White Noise Generator

All three "colours" are steady, random noise; they differ in how the energy is spread across frequencies. White noise has equal energy at every frequency and sounds like a hiss or an untuned radio. Pink noise tilts the energy towards lower frequencies and sounds fuller, like steady rain; several sleep studies used pink noise and found deeper slow-wave sleep. Brown noise tilts further and sounds like a distant waterfall or a low rumble, which many people find the most comfortable for long periods. The natural sounds here (rain, ocean, forest, fan, fireplace) are looped recordings and can be mixed with any colour of noise at independent volumes. Mixes are saved on this device.

Most sleep disruption comes not from noise as such but from changes in noise: a door, a car, a partner turning over. A steady background raises the threshold that a sudden sound must exceed to register, so fewer events reach you. The same masking effect is why open-plan offices feel more private with a fan running, and why some people focus better with rain sounds than with silence. Research on infants finds that white noise shortens the time to fall asleep; for adults the evidence is mixed but the effect on sleep continuity in noisy environments is consistent.

• Volume. Keep it low: about the level of a quiet conversation (around 50 dB), and lower for children and babies, whose ears are more sensitive. If you have to raise your voice over it, it is too loud.
• Distance. Place the speaker across the room, not next to the pillow or the cot.
• Sleep timer. The built-in timer fades the sound after 15 to 120 minutes; once asleep you do not need it, and stopping it protects hearing and battery. The standalone sleep timer works with other audio.
• Consistency. The brain habituates: using the same sound at the same volume nightly makes it a cue for sleep.
• Tinnitus. Many people with tinnitus find low-level broadband noise makes the ringing less noticeable, which is the principle behind clinical sound therapy; discuss it with an audiologist.

For a daytime rest, the nap timer; for focused work with sound in the background, the focus timer; to wind down before switching the sound on, the breathing exercise. Our sleep guide covers the rest of the evening routine.