You've heard the numbers: keep it at 50 dB. No, 60. Actually, some experts say 70 is fine. Which one is right? If you've Googled this before, you've probably walked away more confused than when you started. Let's settle this properly — with the actual studies, not opinions. Also read our guides on whether white noise helps babies sleep and comparing noise colours.
In 2014, the American Academy of Pediatrics tested 14 popular white noise machines at maximum volume. All 14 exceeded 50 dB at the cot. Three of them hit over 85 dB at just 30 cm — that's lawnmower-level noise, next to a newborn's head. The AAP's conclusion: keep white noise at 50 dB or below, and place the machine at least 2 metres from the cot.
Dr. Harvey Karp (author of The Happiest Baby on the Block) recommends 55–70 dB — significantly louder than the AAP. His reasoning: the womb is roughly 75–90 dB loud, so babies are wired to calm at higher volumes. This is true — the womb IS loud. But the womb is also muffled by amniotic fluid and tissue, and exposure is 24/7 for 9 months, not 12 hours overnight for years. The AAP's 50 dB limit is based on hearing safety over time, which is the more relevant measure for nightly use.
Our recommendation: Follow the AAP's 50 dB limit — not Dr. Karp's 70 dB. The AAP's position is based on audiology research and hearing damage risk. Louder white noise may work faster, but it's not worth the long-term risk to your baby's hearing.
Red Nose Australia doesn't publish a specific decibel number, but their safe sleep guidelines include key principles that apply directly:
Red Nose's focus is on preventing SIDS and fatal sleep accidents — not hearing damage. That's why they emphasise distance (cord safety) over decibels. But the two go together: 2 metres away + 50 dB or below = both cord-safe and hearing-safe.
This is the single most important rule, and the one most parents get wrong. Sound intensity drops by 6 dB every time you double the distance. Here's what that means in practice:
| Machine Volume | At 30 cm (next to cot) | At 1 metre | At 2 metres ✅ |
|---|---|---|---|
| Set to 50% | ~65 dB ⚠️ | ~53 dB ⚠️ | ~47 dB ✅ |
| Set to 75% | ~75 dB 🚫 | ~63 dB ⚠️ | ~57 dB ⚠️ |
| Set to 100% | ~85 dB 🚫 | ~73 dB 🚫 | ~67 dB 🚫 |
A machine at 50% volume, 2 metres away — that's the sweet spot. You can see why distance matters more than the volume dial. Even a machine at 100% is unsafe at 2 metres if it's a powerful model.
You don't need special equipment. Download a free decibel meter app:
Then test like this:
Quick at-home test without an app: Stand next to the cot with the machine running. If you can hold a normal conversation without raising your voice, the volume is likely safe. If you have to speak up, turn it down. This isn't precise but it's better than guessing.
Yes — if played too loud or too close. Babies' ear canals are smaller and narrower than adults', which means they amplify sound more. A 2024 study published in ScienceDirect found that some white noise machines produce up to 91 dB at close range — equivalent to a motorcycle engine.
The damage is cumulative. A single night at 70 dB won't cause hearing loss. But 70 dB every night for 2 years adds up. Hearing damage from noise exposure is often gradual and permanent — by the time you notice a problem, the damage is done.
Babies' hearing sensitivity changes as they grow. Here's a practical guide:
| Age | Max Safe dB | Distance | Notes |
|---|---|---|---|
| 0–3 months | 45–50 dB | 2 metres | Most sensitive period. NICU limit is 45 dB |
| 3–12 months | 50 dB | 2 metres | AAP guideline applies |
| 12–24 months | 50 dB | 1.5–2 metres | Same limit, slightly less strict on distance |
| 2+ years | 50–55 dB | 1.5 metres | Still follow the 50 dB guideline where possible |
Bottom line: 50 dB at 2 metres covers all ages. If you remember one number, that's the one. Read our guide on weaning off white noise when you're ready to phase it out.
50 dB or below at the cot — about the volume of a quiet conversation or gentle rainfall. Every white noise machine tested by the AAP in 2014 exceeded 50 dB at maximum volume, so never use full power. Start at the lowest volume that helps your baby settle, and place the machine 2 metres from the cot.
50 dB or below measured at the cot is the safe limit. In hospital NICUs the limit is even stricter at 45 dB. The 55–70 dB range suggested by some sources is not supported by audiology research for continuous overnight exposure. When in doubt, quieter is safer.
Yes. Some machines can produce 91+ dB at close range. Sustained exposure above 70 dB can cause gradual, permanent hearing loss. Babies' smaller ear canals amplify sound, making them more vulnerable than adults. The damage accumulates over time — a few loud nights won't hurt, but months of loud white noise can.
2 metres minimum — recommended by both the AAP and Red Nose Australia. Distance is more important than volume because sound drops by 6 dB every time you double the distance. A machine at 70 dB right next to the cot drops to about 50 dB at 2 metres — that's the difference between unsafe and safe.
We tested 6 machines available in Australia — all checked for safe decibel levels at 2 metres.
See Best White Noise Machines →