# NoiseLedger: Decibel Meter — dB, SPL, noise & sound log

> dB, SPL, noise & sound log (iPhone/iPad app by lapnito.cz s.r.o..)

- Source: https://appshunter.io/ios/app/noiseledger-decibel-meter/id6450401003 (this page in markdown: same URL + `.md`)
- Developer: [lapnito.cz s.r.o.](https://appshunter.io/developer/1577358577)
- Category: Utilities
- Price: Free
- Age rating: 4+
- Requires: iOS 15.0 · 27 MB
- Languages: American English, Czech
- Released: 2026-04-10
- Data updated: 2026-08-29
- User reviews in markdown: https://appshunter.io/ios/app/noiseledger-decibel-meter/id6450401003/reviews.md

## What is NoiseLedger?

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.


## Version history (last 2 releases)

### 2.0 — 2026-08-25

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.

### 1.0 — 2026-04-10

No release notes.

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All apps by lapnito.cz s.r.o.: https://appshunter.io/developer/1577358577

## Related topics

[skc smartwave db](https://appshunter.io/ios/topics/skc-smartwave-db)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-29.*