Sound Meter: Noise Log & dB

Most sound meter apps show you a number and stop there. Sound Meter logs it - so you have a record of what you heard, not just a glance at it.

Whether it's a noisy neighbour, a loud workplace, or checking a nursery is quiet enough, a single reading rarely tells the whole story. A log over time does.

★ Real-time decibel meter
Point your phone and see the noise level instantly, with a plain-language quiet/moderate/loud/dangerous zone. The "loud" line (70 dB) follows U.S. EPA and WHO guidance on average noise exposure, and the "dangerous" line (85 dB) follows the NIOSH recommended exposure limit. The "quiet/moderate" line (50 dB) is our own choice. Links to every source are below and inside the app.

★ Log a session, not just a glance
Start a session and Sound Meter tracks minimum, average and maximum noise over time - minutes or hours. Add a note. Come back later and see exactly what happened, when.

★ Export a report
Turn a logged session into a PDF with the graph, stats and your note, ready to attach to an email. Or export the raw data as CSV.

★ Free, with one small banner
The free version shows a small banner ad - no full-screen ads, no "watch an ad to continue." One optional one-time unlock removes the ads and adds unlimited history and export. Pay once, or don't pay at all.

★ Works offline
No account needed, and the meter works without an internet connection. Your measurements and sessions are processed on your device and stored locally. Ads are provided by Unity Ads, which may use device identifiers and approximate location (see our privacy policy).

★ Honest about its limits
Phone microphones aren't calibrated lab equipment, and we say so. Readings are estimates for everyday use. You can add a calibration offset in Settings.

Free
• Live decibel meter with sourced noise zones
• Session logging with graph
• Last 3 sessions or 24 hours of history
• Notes on every session
• Small banner ad

Sound Meter Pro - one-time unlock
• No ads
• Unlimited session history
• PDF export
• CSV export - raw data for your own records
• No subscription - pay once, keep forever

Sources
• NIOSH (U.S. CDC) - 85 dBA averaged over an 8-hour workday, recommended exposure limit: https://www.cdc.gov/niosh/noise/about/index.html
• U.S. EPA - 70 dB averaged over 24 hours to prevent measurable hearing loss: https://www.epa.gov/archive/epa/aboutepa/epa-identifies-noise-levels-affecting-health-and-welfare.html
• WHO Environmental Noise Guidelines for the European Region (2018) - 70 dB LAeq,24h for leisure noise: https://www.who.int/europe/publications/i/item/9789289053563
• NIDCD (U.S. NIH) - typical levels of everyday sounds: https://www.nidcd.nih.gov/health/noise-induced-hearing-loss

Disclaimer
Sound Meter is not affiliated with WHO, EPA, NIOSH or any government agency. Phone microphones are not calibrated instruments; readings are estimates and not for legal or medical use.

Recent changes:
Added links to the official sources behind the noise zones (NIOSH, U.S. EPA, WHO and NIH) on the meter's info sheet and in a new Sources and disclaimer section in Settings. Sound Meter is not affiliated with any government agency; readings are estimates.