White noise for baby sleep

What this sound is

White noise is every frequency the human ear can hear, roughly 20 Hz to 20 kHz, playing together at equal power. The name comes from light: just as light containing every colour looks white, sound containing every frequency is called white. Because the ear is more sensitive to high frequencies, white noise sounds bright and hissy, a little harsh, like radio static or a shower left running. Pink and brown noise belong to the same family with the highs rolled off, so they sound softer. The white noise in Agubu is there, as the card puts it, to mask sudden sounds: doors, traffic, conversation. It plays as a flat, steady hush for as long as you need, because what wakes a baby is usually not the sound itself but a sudden change in it.

Why it may help

There are two plausible explanations. First, the womb was not a quiet place: before birth your baby heard a continuous low rumble made of blood flow and the sounds of your body, so silence after birth is unfamiliar. Second, masking: with a steady hum in the background, a door closing, a car horn or a conversation next door stands out less. On the evidence, the honest answer is weak and mixed. Small studies suggest it helps some babies fall asleep faster, but participant numbers are low and results do not repeat in every study. Nothing shows it works for every baby. The practical advice: try it for a week and let your Agubu sleep log tell you.

Safe use

The bright, high-frequency character of white noise is tiring at high volume, which is why level and distance matter here most of all. These rules are the same as in the in-app white noise guide.

• Keep the volume low: the level recommended for hospital nurseries is about 50 decibels. The practical test is simple: if you can talk in a normal voice in the room and still be heard easily, the level is fine; if the sound drowns you out, it is too loud.
• Do not put the phone or speaker in the cot or on its edge. Keep it at least one to two metres away, and avoid headphones, sound toys attached to the cot and any speaker close to the baby's ear.
• Use the timer. Fading the sound out 20 to 30 minutes after your baby has fallen asleep is usually enough. If you leave it on through the night, keep the level genuinely low.
• Turn it down once your baby has settled, and do not let a loud setting become the habit even briefly. Do not leave it running all day while your baby is awake, because it masks the speech they learn from.
• If your baby does not react to loud sounds, or the newborn hearing screen was missed or inconclusive, ask your paediatrician before relying on any sleep sound.

How to play it in Agubu

1. Open Agubu, go to the Sounds tab at the bottom and tap the White noise card under Noise. This sound is in the free tier; there is no account to create and nothing to download, it plays on your device offline.
2. Set the volume with your own ears first: if you can speak in a normal voice in the room and still be heard, it is low enough. Place the phone one to two metres from the cot.
3. Tap Timer and pick a duration. When it runs out the sound does not stop abruptly; it fades down slowly. Twenty to thirty minutes after your baby has fallen asleep is enough on most nights.
4. If you like, layer it in the Mixer: a quiet heartbeat under white noise is a common blend. The Mixer is a Premium feature and blends up to four sounds at separate levels. Sounds play without ads and the app needs no internet connection.

Why an app instead of an hour-long YouTube video

There is a reason the search "white noise no ads" lands on YouTube: hour-long videos do work, but they clash with baby sleep in three places. Ads tend to arrive right at the moment of falling asleep and louder than the video; when the video ends the sound stops abruptly, and what wakes a baby is not the sound but its sudden change; and on free YouTube the sound stops when you lock the screen or switch apps.

• Sounds in Agubu play on your device: no internet, no data, no download; they keep going in airplane mode.
• No ad ever cuts in; the sound plays uninterrupted for as long as you want.
• The sleep timer fades the sound down slowly instead of cutting it off.

White noise is one of the eight free sounds; it plays without an account or a download. Volume and distance rules are in the safe-use section above.

When to use it

• During the evening fussy hour, low in the background while you rock or hold your baby.
• At the nap transition, to mask the everyday sounds of the house: kitchen, doors, the street.
• When travelling or in an unfamiliar room, to carry the familiar sleep setting with you.