NoiseLedger: Decibel Meter for iPhone and Android

Overview

What it is, in plain words.

NoiseLedger: Decibel Meter measures sound levels in real time and keeps a noise log you can export as a PDF report. It offers A, C and Z weighting, a noise dosimeter to NIOSH and OSHA standards, spectrum views and overnight recording. According to the store listing, audio is analyzed live and never recorded or stored, and there is no ad, account, subscription or cloud.

What is it?

NoiseLedger: Decibel Meter is a sound level meter and noise logger that records measurements, not audio, and turns them into reports.

What problem does it solve?

A reading of the noise right now does not prove what happened over a night or a workday. NoiseLedger logs levels over time and exports a report showing when a threshold was exceeded, which is useful for documenting neighbor, traffic or construction noise.

Features

Everything it can do.

Real-time dB meter
Show decibels with FAST or SLOW response and MIN, Leq and MAX values.
Frequency weighting
Choose A, C or Z weighting.
Calibration
Use a calibration wizard to match a reference meter, with clipping detection that warns when the microphone reaches its limit.
Noise dosimeter
Track live dose %, TWA and time to the daily limit under NIOSH (85 dB, 3 dB) or OSHA (90 dB, 5 dB) rules.
Statistics
See percentiles L10, L50, L90 and L95, time above a threshold and a full dB histogram.
Spectrum views
View an FFT spectrum with peak frequency, a scrolling spectrogram and 31 third-octave bands with peak hold.
Overnight recording
Log long sessions with adaptive sampling, an auto-stop timer and a quiet night preset.
Reports and history
Export multi-page PDF reports and CSV or PNG files, and search a session history with filters, tags and notes.

Screenshots

See it up close.

How it works

Up and running in three steps.

Calibrate
Run the calibration wizard against a reference meter if you have one.
Measure or record
Watch live levels, or start a long session such as an overnight log with a threshold.
Export the report
Open the session in your history and export a PDF, CSV or PNG.

Who it is for

Is it for you?

People documenting neighbor, traffic or construction noise for a landlord or council, workplace noise checks, concert and workshop goers who care about hearing protection, and anyone checking whether a room is too loud. Readings are approximate and it is not a certified instrument.

Get the app · App Store Get the app · Google Play

Privacy and permissions

Private by design.

The store listing says audio is analyzed live and never recorded or stored, with no accounts, analytics, trackers or cloud, and that you can erase all data from Settings. The Android version works fully offline. The app uses the device microphone to measure sound levels.

Read the privacy policy

No ads
No tracking
Works offline

FAQ

Questions, answered.

Does NoiseLedger record my audio?

No. Audio is analyzed live and never recorded, stored or uploaded.

How accurate is it?

It uses the phone's built-in microphone, so readings are approximate and vary by device, and the calibration wizard can improve them. It is a helpful indicator, not a certified instrument.

Can I use it as evidence of noise?

You can export a PDF report with a threshold-exceedance table showing start, end, duration and maximum. For legal or workplace-compliance measurements, use a calibrated Class 1 or Class 2 sound level meter.

What is the dosimeter?

It tracks noise exposure against NIOSH (85 dB, 3 dB) or OSHA (90 dB, 5 dB) standards and shows dose %, TWA and the time left to the limit.

Can it record overnight?

Yes. Overnight and long-session recording uses adaptive sampling, an auto-stop timer and a quiet night preset.

Is it free?

Yes. The store listing says it has no ads, account or subscription, and the pro metrics are free.

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