Sound Meter: Decibel & Noise

Sound Meter turns your phone into a sound level meter. Measure the noise around you in decibels, keep every session, and turn the record into a document you can hand to someone else.

■ Measure
· Live dB with min, average (Leq) and max
· 1-minute Leq and Lmax — the two figures noise standards are written in
· A-weighted readings (dBA), the curve that follows how loudness is heard
· Live waveform, so you can see the moment a bang lands
· Microphone calibration — offset your phone against a reference meter, up to ±10 dB
· Sample rate — 5, 10 or 20 readings per second

■ Keep the record
· Every session is saved: Leq (1 min), difference against the baseline, sample count
· Session detail with a dB-over-time chart and the raw sample list
· Optional audio recording (m4a) captured alongside the readings, for playback later
· Add a place, a noise type and a memo to any session — all optional, and editable afterwards
· Six noise types: footsteps, dragging furniture, slamming door, TV / music, vibration / machinery, other. A fixed set, so a month of entries can actually be counted
· Export any session to CSV

■ Noise report
· Pick a period and read the pattern: days measured, sessions, night sessions, average length, the hour noise happens most, frequency by noise type
· Peak dB by hour, with daytime (06–22) and night (22–06) kept apart
· Compare against a baseline you choose in Settings: Korean apartment floor-noise baseline (reference), WHO reference lines, or no baseline at all
· The app states the difference in decibels — "+6.3 dB against the baseline" — and leaves the conclusion to you

■ PDF record report
· Timestamps, statistics, the baseline comparison and the calibration offset that was applied, laid out on A4
· Which baseline was used is printed on the report itself
· Share or print it straight from the app

■ What these readings are
The readings come from the microphone built into your phone, so treat them as reference values. They do not replace a certified sound level meter conforming to IEC 61672 class 1 or class 2. Phone hardware, a case over the microphone, automatic gain control, wind and handling noise can all make the same sound read differently. You set the calibration offset yourself, and every PDF states the offset that was used.

The app places your readings next to a baseline and reports the gap. It does not decide whether a rule or a law has been broken. An official determination is only possible through measurement carried out under the applicable statutory method.

■ Privacy
Measurements, notes and recordings stay on this device. There is no account to create and nothing is sent to a server. The app does not collect location. Your files leave the phone only when you export or share them yourself.

Measurement runs while the app is open. It stops when the app goes to the background — the operating system replaces background microphone input with silence, and a record padded with silence is worth nothing.

Free, funded by ads. A one-time in-app purchase removes every ad placement and lifts the export limit.

Made by CodeSand Co., Ltd.