NoiseLedger: Decibel Meter

dB, SPL, noise & sound log

Only for iPhone

Free

iPhone

Pro noise metrics that other apps charge for: NIOSH/OSHA dosimeter, percentiles, spectrogram, third-octave bands and multi-page PDF reports. Free, no ads, fully offline. NoiseLedger is a privacy-first decibel meter and noise log for iPhone. Measure sound levels in real time, run overnight recordings, and export professional reports — with no ads, no account, no subscription, and no cloud. MEASURE WITH CONFIDENCE • Real-time dB with FAST/SLOW response, MIN / Leq / MAX • A, C and Z frequency weighting • iOS measurement mode: audio processing is switched off so readings are not altered • Calibration wizard plus built-in offset profiles for ~30 iPhone models • Honest clipping detection warns you when the mic reaches its limit PRO METRICS, COMPLETELY FREE • Noise dosimeter to NIOSH (85 dB, 3 dB) and OSHA (90 dB, 5 dB) standards • Live dose %, TWA and time-to-limit projection • Percentiles L10 / L50 / L90 / L95 • Time above threshold and a full dB histogram SEE THE SOUND • FFT spectrum with peak frequency readout • Scrolling spectrogram (waterfall) • 31 third-octave bands with peak hold DOCUMENT AND PROVE IT • Multi-page PDF report: chart, statistics, percentiles, dose and a threshold-exceedance table with start, end, duration and max • CSV and PNG export • Overnight and long-session recording with adaptive sampling, auto-stop timer and a quiet night preset • Session history with search, date and dB filters, tags, notes and markers • Trends dashboard: daily Leq, streaks, loudest day and hour PRIVACY BY DESIGN Audio is analysed live and never recorded or stored. No accounts, no analytics, no trackers, no cloud. Everything stays on your iPhone. You can erase all data at any time from Settings. ACCURACY NOTE NoiseLedger uses the built-in iPhone microphone, so readings are approximate and vary by device. It is a helpful indicator, not a certified instrument. For legal, workplace-compliance or safety-critical measurements, use a calibrated Class 1 or Class 2 sound level meter.

Ratings & Reviews

  • 5.0
    out of 5
    1 Ratings

NoiseLedger 2.0 is our biggest update yet — and everything is still free, with no ads. NEW: Noise dosimeter with NIOSH and OSHA standards, live dose %, TWA and time-to-limit projection. NEW: Percentiles L10/L50/L90/L95, time above threshold and dB histogram. NEW: Spectrogram waterfall and 31 third-octave bands with peak hold. NEW: Multi-page PDF report with a threshold-exceedance table — ideal for documenting a noise problem. NEW: Overnight recording with adaptive sampling, auto-stop timer and a quiet night preset. NEW: Trends dashboard with daily Leq, streaks and your loudest day and hour. NEW: Calibration wizard and offset profiles for ~30 iPhone models. NEW: iOS measurement mode disables audio processing so readings are not altered. NEW: History search, date and dB range filters, multi-select export and bulk delete. NEW: Share your settings as a QR preset. NEW: 43 languages. Thank you for measuring with NoiseLedger.

Version 2.0

The developer, lapnito.cz s.r.o., indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    Seller
    lapnito.cz s.r.o.
    Size
    27.9 MB
    Category
    Utilities
    Compatibility
    Requires iOS 15.0 or later.
    • iPhone
      Requires iOS 15.0 or later.
    • iPod touch
      Requires iOS 15.0 or later.
    Languages
    English and Czech
    Age Rating
    4+
    Copyright
    Copyright © 2026 lapnito.cz s.r.o.
  • Privacy Policy

    • More by lapnito.cz s.r.o.

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