Sound Meter: dB Noise Meter

Sound Meter turns your phone into a fast, accurate decibel meter, a true SPL meter (sound pressure level meter) and noise meter you can trust for everyday noise checks. Whether you're checking workplace noise levels, sizing up a concert, tracking traffic outside your window, watching over a baby's room at night, or troubleshooting a noisy HVAC unit or machine, Sound Meter shows you exactly how loud things really are, in real time, with a clean always-dark gauge that's easy to read even in a dark room.

Live decibel meter
• Big, live dB readout on a NIOSH-coded color gauge, green under 70 dB, sliding through yellow and orange to red above 105 dB, so you spot the danger zone at a glance
• Min, average, max and LEQ (equivalent continuous level) stats update as you go
• Switch between dBA and dBC weighting, and Fast (125 ms) or Slow (1 s) response, just like a professional dB meter

Rotating alarm bezel (new)
• Drag the yellow arrow around the dial to set your own alarm threshold, in dB
• Cross it and your phone vibrates and the readout turns red, perfect for keeping music, tools or a noisy room under a limit without staring at the screen

Hearing protection, built in
• A live "safe exposure time" estimate based on NIOSH/WHO guidelines, 85 dB is safe for about 8 hours, and that time halves every time the level climbs 3 dB higher
• Turns abstract decibel numbers into a plain answer: how long can I stay here safely?

Record, even in the background
• Start a session and keep measuring while you use other apps, a foreground service with a persistent notification and stop button keeps recording alive, with a watchdog that auto-resumes if the system interrupts it
• Only sound levels are recorded, never audio. Nothing is ever listened to, stored as a recording, or transmitted anywhere

History, sharing & export (new)
• Full recording history with a scrolling waveform view
• Share a session as a premium, always-dark stats image, graph, key numbers and a QR code, ready for a report or a quick message
• Export the full session as CSV for spreadsheets and further analysis
• Turn any recording into a short animated video of the dB graph, ready to share

Built for real use
• Calibration offset slider (−15 to +15 dB) to correct for your phone's microphone
• 110 in-app languages
• Tablet and Chromebook layouts

Honest by design
Sound Meter is free, with one small banner ad, no popups, no video ads, and no "no ads" claims because there is one. And no subscription: recording, history, CSV and video export are all included, not locked behind a paywall. Your phone's microphone was never certified for acoustic measurement, so treat every reading as a well-calibrated estimate, not a medical or legally certified sound level meter. Use the calibration slider to bring it closer to a reference meter for your device, and use good judgment for anything safety-critical.

Sound Meter, a noise meter and hearing-health companion for anyone who wants to measure noise, watch dB levels over time, and protect their hearing.

Popular uses: an SPL meter with dBA and dBC weighting, record the noise level over time at a concert, in the office or during a loud night, check safe exposure times based on NIOSH and WHO limits, and set a vibration alarm at a dB threshold.