Sound Level Meter: Decibel dB

Sono is a clean, easy-to-read sound level meter that turns your phone into a real-time decibel meter. Measure how loud anything is, right now, in dB(A).
No sign-up, no login, fully offline.

Checking a noisy restaurant, a concert, your AC or PC fans, road and traffic noise, a snoring partner, a baby's room, a workplace or machine shop, or a neighbour's music? Sono shows the sound pressure level (SPL) instantly with a clear live reading, an animated dial, and a scrolling graph.

Why Sono
• Fully offline. No account, no login. Your audio is never recorded or stored and never leaves your device.
• Live dB(A), min / average / max, real-time graph, history and calibration, included.
• Honest readings. A per-device calibration offset lets you trim the reading to match a reference.

Features
• Live decibel meter with a large, easy-to-read dB number
• A, C and Z frequency weighting: dB(A), dB(C), dB(Z)
• Min, average and max for every session
• Real-time scrolling graph, from 30 seconds up to 30 minutes
• Peak hold marker on the dial
• Session timer with pause and resume
• Calibration offset to match a reference level
• Three gauge styles: circular, semicircular, and analog needle
• Reference guide: how loud common sounds are, from a whisper to a jet
• Save measurements with labels and notes, then browse your history
• Add timestamped marks while measuring
• Dark mode that remembers your choice, plus optional haptics
• Lightweight and fast, opens straight to a live reading

How Loud Is It? Quiet library ~30–40 dB · normal conversation ~60 dB · busy traffic ~70–80 dB · lawn mower ~90 dB · nightclub ~100 dB · rock concert ~110 dB. Sono labels the live reading against everyday sources so the numbers actually mean something.

Great For
• Checking whether a venue, restaurant or workplace is too loud
• Settling neighbour noise disputes
• Calibrating speakers, home theatre and audio gear
• Measuring appliances, fans, engines and machinery
• Anyone curious how loud their world really is

A Note on Accuracy: Phone microphones are tuned for voice and can clip at very high volumes, so readings are approximate. Sono is a reference tool and is not a replacement for a certified sound level meter (SLM). Use the calibration offset to align Sono with a known reference for more reliable results.

Sono is not a medical device and does not diagnose, treat, cure, or prevent any medical condition. Not a certified sound level meter, for reference only.

Sono: the simple, offline decibel meter.