**Reads the room. Never records it.**

SoundGauge turns your phone into a sound level meter with an instrument you can actually read: an engraved dial, a needle that moves the way a real meter moves, and a peak-hold marker that parks at the loudest moment so you don't miss it.

Open the app and you get the level in decibels, the running minimum, average and maximum, and a rolling 60-second trace of how the noise has been behaving. Nothing to sign up for, nothing to configure.

**WHAT PEOPLE USE IT FOR**
- Checking whether a gym, bar or restaurant is as loud as it feels
- Documenting a noisy neighbour, road or building site over time
- Sanity-checking an open-plan office, classroom or factory floor
- Finding the quiet corner of a house, and the loud one
- Seeing how loud a workshop tool really is before spending an hour with it

**MEASUREMENT**
- A, C and Z frequency weighting — A follows human hearing, C keeps the bass, Z is unweighted
- Fast (125 ms) and Slow (1 s) time response
- Peak-hold marker on the dial, with a 3-second decay
- Calibration offset, stored per device, with a guided "match a reference meter" flow
- Dial range 30–130 dB

**SESSIONS**
- Record a session and keep the whole trace, not just a snapshot
- L(Aeq), L(Amax), L(Amin), L10, L90 and peak for every recording
- Noise dose shown as a share of the 8-hour NIOSH allowance
- Keeps measuring with the screen off
- Export any session as CSV, or share it as an image

**ALERT LEVEL**
- Set a threshold — 85 dB by default, where long exposure starts doing damage
- Vibration and an on-screen flash. No chime, because a sound from this phone would be measured as room noise
- Choose how long the level has to hold before the alert fires, so a single door slam doesn't trigger it

**LEVELS REFERENCE**
A built-in table of everyday sounds from a whisper to a siren, each with the daily exposure time NIOSH considers safe without hearing protection. A raw number means nothing until it sits next to a vacuum cleaner.

**PRIVACY — THE SHORT VERSION**
No audio is ever recorded, saved or transmitted. The microphone stream is converted to a level and discarded frame by frame. There is no account, no analytics, no advertising, no tracking and no network code in the app at all — SoundGauge works in airplane mode, and there is nothing for it to upload. Your sessions are stored on your device and deleted with the app.

The microphone is the only permission requested.

**ACCURACY — WORTH READING**
Phone microphones are tuned for speech, not for measurement, and two handsets in the same room can differ by several decibels. Most compress or clip somewhere near 100–110 dB, so very loud readings under-report. A case, a pocket, wind, or a hand over the mic will change a reading more than anything in this app.

SoundGauge is not a Class 1 or Class 2 sound level meter under IEC 61672. Readings are not evidence for OSHA, workplace, legal or insurance purposes, and the app cannot diagnose hearing damage — for that, see an audiologist. Use it to compare and to notice: this room against that one, tonight against last night.

Made by RIGPA Tech.