Measure real‑time environmental noise using your device’s microphone. Get instant dB SPL (simulated), A‑weighted level, and hearing safety recommendations. Includes an educational guide on decibel scales, noise regulations, and hearing conservation.
The decibel is a logarithmic unit that expresses the ratio of a physical quantity (usually sound pressure) to a reference level. In acoustics, dB SPL (Sound Pressure Level) uses 20 µPa as the reference — the threshold of human hearing. Because the human ear responds non‑linearly, we often apply A‑weighting (dBA) to mimic the ear’s sensitivity. This meter simulates A‑weighted levels using your device’s microphone (uncalibrated, for educational use).
Lp = 20 · log10(p / p0) dB SPL
where p is root‑mean‑square sound pressure, p0 = 20 µPa.
From occupational safety (OSHA, NIOSH) to community noise ordinances, understanding sound levels helps prevent hearing loss and environmental disturbance. The NIOSH recommended exposure limit is 85 dBA for 8 hours — every 3 dB increase halves the safe exposure time. Our meter, though not calibrated, illustrates these risks and encourages awareness.
| Sound source | Typical level (dBA) | Risk / comfort |
|---|---|---|
| Breathing, quiet recording studio | 10 – 20 dB | Very quiet |
| Library, quiet bedroom | 30 – 40 dB | Quiet |
| Normal conversation (1 m) | 55 – 65 dB | Moderate |
| Busy street, vacuum cleaner | 70 – 80 dB | Loud; possible annoyance |
| Heavy traffic, lawnmower | 80 – 90 dB | Risk with prolonged exposure |
| Motorcycle, jackhammer (10 m) | 90 – 100 dB | Hearing damage after 30 min |
| Rock concert, ambulance siren | 100 – 110 dB | Immediate risk; use protection |
| Jet takeoff (25 m), gunshot | 120 – 140 dB | Threshold of pain; instant injury |
A software company measured ambient noise in an open‑plan office: average 62 dBA with peaks to 75 dBA (conversations, phone rings). According to World Health Organization (WHO) guidelines, background noise in offices should not exceed 35 dBA for steady noise and 45 dBA for intermittent noise to prevent distraction. The company introduced acoustic panels and quiet zones, reducing average levels by 8 dBA, which improved reported concentration by 34%.
A‑weighting (dBA) is the most common for environmental and occupational noise because it approximates the human ear’s response at moderate levels. C‑weighting (dBC) is flatter and used for peak measurements (e.g., gunfire, machinery). Z‑weighting (dBZ) is zero‑weighting (flat). Our meter uses an A‑weighting simulation based on a 2nd‑order high‑pass filter (per IEC 61672).
Sound pressure level in decibels is Lp = 20 log₁₀(prms/pref) with pref = 20 µPa. A factor of 10 in pressure ratio corresponds to 20 dB. Because our microphones output digital signals (full scale ±1), we map 0 dBFS (digital maximum) roughly to 120 dB SPL, assuming typical headroom. This is a crude approximation — actual smartphone microphones vary. Use this meter as an educational tool, not for legal or medical decisions.
About this tool: Developed by the GetZenQuery team based on publicly available acoustics principles and references from ISO, NIOSH, and WHO. It is intended for educational and demonstration purposes only. Last content update: March 2026.