Ocean waves for baby sleep

What this sound is

The ocean sound has two layers. Underneath is the deep, continuous hum of the sea heard from a distance, close to brown noise; on top is the broadband wash of each wave spreading over the sand, swelling and fading. On a beach that wash swells as the wave comes in and fades as it draws back; the ear hears it like breathing in and out. In Agubu a wave arrives every nine seconds, as the card says: a slow, regular rhythm. Of the nature sounds it changes most slowly: rain and stream run on, while the ocean rises and falls in a soft rhythm.

Why it may help

What the ocean shares with the noise family is the continuous hum underneath: it resembles the womb and masks sudden household sounds. What sets it apart is the rhythm. A slow, regular swell and fade carries a pattern like rocking or slow breathing, and some babies, like some adults, settle to that more than to a flat hum. That variation can also be a drawback: a very light sleeper may notice household sounds in the quiet moments between waves. On the evidence, we know of no study of wave sounds in babies, and the general evidence for steady sounds is weak and mixed. Try it low for a few nights and read Agubu's sleep log.

Safe use

The loudness rises as each wave comes in; set the level at the peak, not in the lull, so that even the peak stays below normal speech. The yardstick is the 50 decibels and one to two metres in the white noise guide; even the crest of a wave should stay under it.

• 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 the rise and fall of the waves wakes a very light sleeper, switch to a flat sound such as rain or pink noise.

How to play it in Agubu

1. Open Agubu, go to the Sounds tab at the bottom and tap the Ocean card under Nature. This sound is part of the Premium library, so the card shows a Premium badge until you subscribe. The eight free sounds and the timer stay open to everyone. It plays on your device offline, with nothing to download.
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: brown noise under the waves fills the gaps between them. 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.

When to use it

• At bedtime while rocking slowly, to match the rhythm of the sound to the rhythm of your arms.
• In the evening hours when the parents want to wind down too, as a background that calms the whole house.
• On holiday or in an unfamiliar room, to carry the sleep setting from home with you.