Sound Meter: SPL & Noise Dose

Sound Meter is a decibel meter (SPL meter) built for people who watch noise levels all day on the job: expo and trade show staff, AV technicians, FOH engineers, event managers and venue safety crews. Put your phone on the booth table or the console and see at a glance whether the room is over its limit.

FREE NOISE DOSE – WE NEVER PAYWALL SAFETY
- Live noise dose using the OSHA method (90 dB criterion, 5 dB exchange rate) and the NIOSH method (85 dB, 3 dB)
- Always computed from the A-weighted Slow level, the way the methods define it
- Estimated time left before 100% dose at the current level
- Dose, statistics and alerts are free, with no time limit

BUILT FOR EVENTS, EXPOS AND VENUES
- Venue presets: Convention Hall, Outdoor Concert, Corporate Ballroom, Breakout Room, Theater, House of Worship, Nightclub
- Custom SPL alert with hold time and hysteresis, so it doesn't flap on a single drum hit
- Vibration when the venue alert or limit is crossed
- Dark screen mode for FOH positions
- Wear OS companion: live dB, Leq and dose on your watch
- Big monospaced digits that don't jitter as the level changes

MEASUREMENTS
- Real-time dB SPL with A weighting and Fast / Slow time weighting
- LAeq, LASmax, LASmin and a true C-weighted peak (LCpeak), not a relabelled maximum
- L10 / L50 / L90 percentiles
- Live timeline and spectrum
- Shows OVER when a sound is louder than the phone microphone can measure, and tells you which readings that affects, instead of silently under-reading

PRO – ONE-TIME PURCHASE, NO SUBSCRIPTION
- C, Z and ITU-R 468 weighting
- 1/3-octave analyzer, 25 Hz to 20 kHz
- Session recording with a PDF report and CSV export: venue, duration, LAeq, LASmax, LCpeak, L10/L50/L90, dose and timeline
- All ads removed
Each Pro feature can also be unlocked free for 24 hours by watching an optional ad. There is never a subscription.

HONEST DSP
- A and C weighting filters are checked against the IEC 61672-1 tolerance tables by an automated test suite
- 44.1 kHz / 16-bit capture from the raw microphone input
- Adjustable calibration offset: match the app to a calibrated reference meter or a 94 dB calibrator
- USB audio input support, so you can use an external measurement microphone with your own calibration offset
- Methodology is documented in the app

PRIVACY
Audio is processed on your phone and never recorded or uploaded as sound. Sessions store levels only, on your device. The free version shows ads; ads are never shown during a recording.

IMPORTANT
Sound Meter is a reference tool, not a certified Class 1 or Class 2 sound level meter or a personal noise dosimeter, and it must not be used for legal or regulatory compliance. Phone microphones vary from model to model and have a maximum level they can measure. For accurate results, set the calibration offset against a calibrated reference.