Background noise can be incredibly helpful for sleep, focus, and relaxation. But like any tool, it needs to be used correctly. The volume that feels comfortable in the moment can still cause damage over time—and this is especially important to understand when using sound machines for babies or children.
Here's what you need to know about safe listening practices to get all the benefits of background noise without risking your hearing health.
Understanding Decibels
Sound intensity is measured in decibels (dB). The scale is logarithmic, which means small increases in decibels represent large increases in actual sound energy. A sound at 85 dB has more than 30 times the energy of a sound at 70 dB—not just 21% more.
Here are some common sounds for reference:
| Sound | Approximate Decibels |
|---|---|
| Whisper | 30 dB |
| Normal conversation | 60 dB |
| Running shower | 70 dB |
| Vacuum cleaner | 75 dB |
| City traffic (inside car) | 80-85 dB |
| Lawn mower | 90 dB |
| Rock concert | 110-120 dB |
The 70 dB Rule for General Safety
According to the National Institute on Deafness and Other Communication Disorders (NIDCD), sounds at or below 70 dB are unlikely to cause hearing damage even after prolonged exposure. This is the benchmark for safe extended listening.
At 85 dB—the level of heavy traffic—hearing damage can occur after about 8 hours of exposure. For every 3 dB increase above that, the safe exposure time is cut in half:
- 85 dB: 8 hours
- 88 dB: 4 hours
- 91 dB: 2 hours
- 94 dB: 1 hour
Since many people use background noise for 8+ hours overnight, keeping the volume well below 70 dB is the safest approach.
Special Considerations for Babies and Children
When it comes to infants and young children, extra caution is warranted. Their auditory systems are still developing, and they're more susceptible to noise-induced damage.
Important: The American Academy of Pediatrics (AAP) has raised concerns about infant sound machines. In 2014, they tested 14 popular infant sleep machines and found that all of them exceeded hospital-recommended noise levels when set to maximum volume.
AAP recommendations for infant sound machine use:
- Distance: Place sound machines at least 7 feet (200 cm) away from the baby's crib or bassinet—never attached to the crib rail or close to the baby's head.
- Volume: Keep the volume at or below 50 dB. This is roughly the level of a refrigerator humming or quiet office environment.
- Duration: Use sound machines for settling and sleep, but consider limiting extended overnight use at higher volumes.
The 50 dB guideline for babies is significantly lower than the 70 dB general adult recommendation because:
- Babies are exposed for longer periods (10-16 hours of sleep per day)
- Their ear canals are smaller, which can amplify sound
- Their auditory systems are still developing
- They can't tell you if something is too loud
How to Check Your Volume
Unfortunately, most sound machines don't display their decibel output. Here's how to check:
Use a smartphone app. Several free apps can measure sound levels with reasonable accuracy:
- NIOSH SLM (developed by the National Institute for Occupational Safety and Health)
- Decibel X
- Sound Meter
To measure, place your phone where your head (or your baby's head) would be during sleep and check the reading with the sound machine running.
Use the conversation test. If you can comfortably hold a normal conversation at arm's length without raising your voice, the sound is likely below 70 dB. If you have to raise your voice significantly, it's too loud.
Use the shower comparison. A running shower is approximately 70 dB. Your background noise should be quieter than standing next to a running shower.
Guidelines for Adults
For overnight use with sleep sounds:
- Target range: 50-65 dB
- Maximum: 70 dB
- Duration: Safe for all-night use at these levels
For focus and productivity during the day:
- Target range: 50-70 dB
- Maximum: 70 dB for extended sessions (2+ hours)
- Brief higher levels: Up to 75-80 dB is acceptable for short periods (under an hour)
Guidelines for Babies and Children
For infants (0-12 months):
- Target range: 40-50 dB
- Maximum: 50 dB
- Distance: At least 7 feet from the crib
- Never: Attach to the crib or place near the baby's head
For toddlers and young children:
- Target range: 50-60 dB
- Maximum: 60 dB
- Distance: Keep device away from the bed
For older children and teens:
- Target range: 50-70 dB
- Maximum: 70 dB
- Education: Teach them about hearing protection
Warning Signs of Volume Problems
Pay attention to these indicators that your sound levels may be too high:
For yourself:
- Ringing or buzzing in your ears (tinnitus) after turning off the sound
- Sounds seeming muffled after prolonged exposure
- Having to significantly increase volume over time to achieve the same effect
- Difficulty hearing high-pitched sounds (doorbells, birdsong)
For babies and children:
- Appearing startled by the sound
- Covering their ears
- Fussiness that starts with sound machine use
- Not responding to normal voices after exposure
If you notice any of these signs, reduce the volume immediately and consult with a healthcare provider if symptoms persist.
The Bottom Line
Background noise is a valuable tool for sleep and focus, but it needs to be used responsibly. For adults, keep volumes at or below 70 dB for extended use. For babies and children, stay at or below 50 dB and maintain proper distance.
When in doubt, err on the side of quieter. A sound that's slightly too quiet can still provide masking and sleep benefits—but a sound that's too loud can cause permanent damage that no amount of caution later can undo.
Your hearing has to last a lifetime. Protect it.