Decibels Downloads & RevenueDecibels: Sound Level dB Meter · App Store

How loud is it, really? The neighbor's bass at 2 a.m. The workshop that leaves your ears ringing. Decibels gives you a number you can trust — and, when you need it, the evidence to back it up.

Decibels is a precision sound level meter built like a real instrument: the IEC 61672 mathematics professionals use, per-device calibration verified against a laboratory-validated reference, and a design that shows what the noise is doing, not just how loud it is.

A · C · Z WEIGHTING · FAST · SLOW · IMPULSE · Leq · LCpeak · SEL
THE REAL MATHS, IN A REAL METER.

MEASURE LIKE AN INSTRUMENT
Every reading is a true IEC-weighted level. Choose A, C or Z weighting and Fast, Slow or Impulse response. Sessions record the energy-averaged Leq, the loudest moment, the C-weighted peak, sound exposure level (SEL) and the L10, L50 and L90 statistical levels used in environmental noise reports. An overload lamp shows when the microphone is clipping, and readings below the microphone's own floor are flagged, not faked. Fine-tune against any reference meter with the built-in guide.

SEE WHAT THE NOISE IS
A number says it's loud; the spectrum says it's a fridge compressor, a bass line or a siren. Switch the meter to a live FFT spectrum analyzer, 1/3-octave bands, or a scrolling spectrogram waterfall that paints frequency against time and identifies a sound by its shape.

NIGHT MODE
Start it at bedtime, set your wake-up time, and put the phone down. In the morning a quiet-hours report shows your night hour by hour: how quiet it was, when the loud moments happened, and how loud they were. Light on battery.

KEEP THE EVIDENCE
Set a threshold and get notified when noise crosses it. Turn on Evidence Clips and Decibels saves a 30-second recording around each event — 10 seconds before, 20 after — stored only on your phone, playable from the session, and shared only when you choose. Built for noise complaints.

PROTECT YOUR HEARING
An exposure dosimeter tracks your daily noise dose against NIOSH, OSHA and EU 2003/10/EC limits: dose percentage, time-weighted average and safe time remaining at the current level. Export sessions to Apple Health as environmental audio exposure.

ALWAYS WITHIN REACH
A Live Activity keeps the meter on your Lock Screen and in the Dynamic Island while you record, Stop button included. Widgets show your last reading and today's dose. Share a session card in one tap, or export CSV data and PDF reports.

PRIVATE BY DESIGN
No ads. No tracking. No analytics. Audio is analysed on your device and never leaves it unless you share a clip or card yourself. Evidence Clips are off by default and require explicit consent.

FREE
- Live meter with A/C/Z weighting, Fast/Slow/Impulse response
- Leq, Max, Min, C-weighted peak and overload indicator
- Calibration trim and reference-meter guide
- Sessions with chart, notes, tags and location (last 10)
- One threshold alert
- Live Activity, widgets, light and dark themes

DECIBELS PRO
- Unlimited session history
- Spectrum ana