dB Toolkit: Sound Level Meter

Most decibel apps show you a number and leave you to argue about it. dB Toolkit is built for the times somebody else has to act on what you measured - a landlord, an environmental health officer, an employer, HOA, a licensing officer.

THE FREE APP IS A COMPLETE SOUND LEVEL METER

Not a demo. The live meter, dBA, dBC and dBZ as real IEC 61672-1 filters rather than labels, Fast, Slow and Impulse time weighting, LAeq, LA10, LA50, LA90, LAmax and Lpeak, the history graph and the peak markers. All free, forever.

HONEST ABOUT ACCURACY

iPhones do not publish a microphone sensitivity, so most sound level apps show a number referenced to nothing at all. This one ships a constant measured against a calibrated reference microphone, states its uncertainty on every report, and says plainly when the phone it is running on has not been measured. Nothing that decides whether a reading is correct is ever behind a paywall.

Some apps charge to unlock A-weighting. A sound level meter without A-weighting is not a sound level meter.

PRO - ONE PAYMENT, NO SUBSCRIPTION

Record a session with the audio alongside it, the place it was taken, and every interruption logged. Keep the history, play it back, trim to the part that matters.

Then hand it on:
- A dated PDF report with the graph, the statistics, the loud events and the scale it was measured on
- CSV of every reading, with the scale, the gaps and the microphone in the header
- Measure against a published limit and get a verdict on the report

Pro also adds the spectrum analyser, octave and third-octave bands, the spectrogram, cumulative noise dose, the signal generator, room measurement, and support for a calibrated USB measurement microphone.

WHAT IT IS FOR

A noise problem nobody is taking seriously. Record the whole episode rather than the loudest instant - when it happened and for how long is the part that carries weight. Measure the background too, because most assessments are about the difference between a sound and the quiet it sits in.

A workplace you are responsible for. Daily exposure and peak, against the Control of Noise at Work Regulations 2005, the OSHA permissible exposure limit and action level, or the NIOSH recommended limit. The app names the standard it used.

A venue or a show with a limit on it. Log it and leave with a timestamped record of what the level actually was.

FULLY OFFLINE

Nothing needs an internet connection, including the report. No ads - an app that plays audio while measuring is contaminating its own reading. Recordings and location stay on your device.

WHAT IT IS NOT

This is a phone, not a Class 1 or Class 2 sound level meter. For a measurement that has to stand on its own in court, you need a calibrated instrument and somebody qualified to use it. What this gives you is a competent, honest, timestamped record with its uncertainty stated - which is very often the thing that is actually missing.

iPhone, iOS 16 and later.

For more info and to provide feedback, contact developer@letsgetstashd.com or visit LetsGetStashd.com

EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/