You've probably heard of white noise. But more parents are asking about brown noise and pink noise too — and whether one is better for baby sleep than the others. The short answer is: it depends on your baby. Here's how to tell which one works best, plus exactly how to use any of them safely. Also read our guides on whether white noise actually helps babies sleep and how to wean your baby off white noise.
| White Noise | Pink Noise | Brown Noise | |
|---|---|---|---|
| Sounds like | TV static, vacuum, shush | Rainfall, heartbeat, waves | Waterfall, distant thunder, plane cabin |
| Frequency | All frequencies at equal volume | More bass, less treble | Deep bass, very little treble |
| Feels | Bright, sharp, constant | Soft, rhythmic, natural | Deep, rumbling, heavy |
| Best for masking | Sudden household noises (doors, dogs) | General ambient noise | Low-frequency noise (traffic, construction) |
| Womb-like? | Closest match — mimics blood flow whoosh | Similar but softer | Less womb-like, more nature-like |
| Common in baby machines? | Almost all | Some models | Rare |
Brown noise — sometimes called red noise or Brownian noise — is the deepest of the three. It drops high frequencies dramatically and emphasises the lowest bass tones. The result is a sound that feels more like a physical sensation than a noise: a low rumble you can almost feel in your chest.
Unlike white noise which tries to be flat across all frequencies, brown noise sounds more like what you'd hear inside a plane cabin or standing near a large waterfall. It's less harsh and many adults describe it as more soothing than white noise for the same reason — no sharp high frequencies to grate on your ears.
There's no formal study comparing noise colours for babies, but paediatric sleep consultants consistently see patterns based on baby temperament.
White noise is the best choice for most newborns. It mimics the whooshing sound babies heard in the womb — a constant 75-90 dB of rushing blood and bodily sounds — and reliably triggers the calming reflex. It's also the most effective at masking sudden household noises like a barking dog, doorbell, or older sibling slamming a door. If you live in a busy house or have other kids, white noise is your safest bet.
Brown noise works better for babies who seem sensitive to high-pitched sounds. If your baby startles at the white noise itself, or seems restless even with white noise playing, try brown noise. Its deeper frequency is less jarring. It's also a good option if your main noise problem is low-frequency disruption — traffic noise, neighbours, or construction — because brown noise masks those deep rumbles most effectively.
Pink noise sits between white and brown. It's often described as more natural-sounding — like rainfall — and some parents find their babies settle faster with it. It's a good middle ground to try if white noise sounds too harsh and brown noise sounds too heavy.
Try this: If your machine lets you switch sounds, test one colour per night for 3 nights each. Keep volume and distance the same. Most parents know within a week which one their baby prefers.
Yes — any colour noise is safe to play all night as long as you follow the same safety rules. The key is volume and distance, not duration. Here's what Red Nose Australia recommends:
Because brown noise has less high-frequency energy at the same volume, some parents wonder if it's gentler on baby ears. In theory, yes — lower frequencies carry less risk of hearing damage at equal volume. But no health organisation has declared one noise colour safer than another. The 50 dB / 2-metre rule applies equally to all of them. Read our full decibel safety guide for the science behind these numbers.
Not all machines offer multiple noise colours. Here's what's available in Australia right now:
See our full white noise machine comparison for sound options on every model we've tested.
White noise is the most studied and most commonly recommended. But the best colour is the one your baby responds to. Start with white noise, test pink noise, then try brown noise if neither feels right. Most babies settle on a favourite within a few nights.
White noise plays all frequencies equally — it sounds bright and static-like. Brown noise drops the high frequencies and deepens the bass — it sounds like a deep rumble or waterfall. Brown noise is gentler on sensitive ears and better at blocking low-frequency sounds like traffic.
Both are safe when used at or below 50 dB at the cot, with the machine at least 2 metres away. Brown noise has less high-frequency energy, so in theory it carries slightly less risk at equivalent volume. But Red Nose Australia does not distinguish between noise colours — the safety rules are the same for all.
Yes. Red Nose Australia's guidelines focus on safe distance and volume, not duration. Many parents play noise all night because sudden silence can wake a baby more than continuous sound. Just keep it at 50 dB or below.
The Glow Sleep Easy is one of the few baby machines that explicitly offers brown noise. The Dreamegg D1 has nature sounds that lean toward brown. Most other machines (Hatch, Welcare) focus on white and pink. Brown noise is more common in adult sleep sound machines and phone apps.
We tested 6 white noise machines in Australia — including models with white, pink, and brown noise options.
See Best White Noise Machines →