Sound Meter
Free online decibel meter | real-time noise level detection
About Sound Meter
Introduction to Sound Meter
Sound Meter is a free, browser-based decibel meter that estimates environmental noise levels in decibels (dB) using your device’s microphone. It provides real-time measurements to help you understand whether your surroundings are quiet, moderate, or potentially harmful to hearing.
The tool is intended for individuals monitoring home or office environments, educators teaching about acoustics, and users seeking awareness of noise exposure. While it offers useful estimations, it is not a substitute for calibrated, professional-grade equipment when compliance-level measurements are required.
Key Takeaways
- Real-time sound level estimates in decibels (dB)
- Displays current, minimum, average, and maximum readings
- Interprets noise levels across common ranges (quiet to dangerous)
- Uses your device’s microphone; audio is processed locally in the browser
- Works on desktop and mobile (browser and hardware quality may affect accuracy)
- Incorporates guidance consistent with NIOSH/CDC and WHO recommendations
- Highlights the logarithmic nature of the decibel scale and the 3 dB exchange rate
- Intended for awareness and education, not for certified occupational measurements
How Sound Meter Works
When you click Start and grant microphone permission, the tool accesses your device’s microphone to estimate sound pressure level (SPL) and present a live dB reading. Your audio is processed locally in the browser and is not recorded, stored, or transmitted to a server. The interface shows the current reading as well as minimum, average, and maximum values over the session.
The meter contextualizes readings using commonly referenced ranges (e.g., quiet, moderate, caution, harmful) and provides reference examples for each range. Because the decibel scale is logarithmic, each 10 dB increase corresponds to approximately a tenfold increase in sound intensity and typically feels about twice as loud. The NIOSH 3 dB exchange rate indicates that safe exposure time halves with every 3 dB increase above 85 dB.
Reference ranges and examples:
| Range (dB) | Category | Examples | Guidance |
|---|---|---|---|
| 0–40 | Quiet | Library (~30 dB), whisper, rustling leaves | Safe for all exposure times |
| 40–70 | Moderate | Normal conversation (~60 dB), quiet office | Generally safe for prolonged exposure |
| 70–85 | Caution | Busy traffic (~80 dB), vacuum cleaner | Extended exposure may cause fatigue |
| 85–100 | Harmful | Power tools (~90 dB), motorcycle | 8+ hours exposure can damage hearing |
| 100–120 | Very Harmful | Chainsaw (~110 dB), siren | Minutes of exposure can cause damage |
| 120+ | Dangerous | Jet engine (~130 dB), fireworks | Immediate hearing damage risk |
Approximate safe exposure time by level (based on NIOSH/CDC guidance):
| Level (dB) | Approximate Safe Exposure | Examples/Notes |
|---|---|---|
| 70 | Unlimited | Safe for all-day exposure |
| 85 | Up to 8 hours | NIOSH recommended 8-hour limit |
| 90 | About 2–4 hours | Lawn mower, motorcycle |
| 100 | About 15 minutes | Hair dryer, power tools |
| 110 | About 1–2 minutes | Rock concert, siren |
| 120+ | Immediate damage risk | Firecrackers, jet engine — avoid exposure |
Note on accuracy: Estimations depend on microphone quality, device model, and lack of calibration. For compliance testing or legal documentation, use a calibrated, professional sound level meter.
Core Benefits and Applications
Sound Meter helps users quickly assess ambient noise and make informed decisions about exposure. It supports awareness, education, and preliminary assessments aligned with widely referenced health guidance from organizations such as NIOSH/CDC, WHO, and NIDCD.
Common applications include:
- Home and office noise checks to maintain comfortable and safe environments
- Classroom demonstrations about decibels, SPL, and the logarithmic scale
- Preliminary assessments of neighborhood or traffic noise
- Quick checks at events, workshops, or makerspaces using power tools
- Personal hearing health awareness and adherence to safe exposure times
For extended or high-level noise exposure, consider hearing protection and consult authoritative guidance. For precise measurements or regulatory compliance, use certified instruments and follow applicable standards.