Car ride sound for baby sleep

What this sound is

What you hear inside a car is several layers. The dominant one is the hum of tyres on the road surface: broadband, low-frequency, close to brown noise. On top sit the steady, slightly higher tone of the engine and the soft hiss of cabin air. Because the cabin filters out the sharp sounds of the outside world, everything sounds muffled and soft, surprisingly close to the womb sound. The card in the app keeps it short: tyre rumble, for babies who sleep in the car. The sound in Agubu is, as the card says, tyre rumble: a continuous, bass-heavy road sound. On a real journey what wakes a baby is the sudden change, a horn, braking, the engine stopping, not the steady hum.

Why it may help

The sleeping-in-the-car effect has two components: sound and motion. On the sound side, the constant low hum resembles the womb and masks outside sounds; the motion can only be imitated at home with your arms or a rocker. The app gives you the first component only; knowing that from the start sets the right expectation. On the evidence, we know of no study of car sounds, and the general evidence for steady sounds is weak and mixed. Not every baby who sleeps in the car will sleep to this at home. For a baby who drops off easily on the road it is a reasonable first try: a few low nights, then the sleep log.

Safe use

A moving car cabin typically sits somewhere around 60 to 70 decibels, depending on the car and the road; do not try to match that at home. Level and distance follow the 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.
• On a real car journey do not add the car sound from the phone; the cabin is already loud enough.

How to play it in Agubu

1. Open Agubu, go to the Sounds tab at the bottom and tap the Car ride card under Household. 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: a low heartbeat over the car sound hints, a little, at the rocking that is missing. 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, for a baby who only sleeps in the car, to ease the move to the cot at home.
• At nap time, when your baby fell asleep on the drive and woke up as you carried them inside.
• On a walk with the pram, when you cannot pick your baby up, as a familiar backdrop.