Live sound meter
An A-weighted sound level meter that runs in your browser. The microphone signal is processed on this device only: nothing is recorded, stored or sent anywhere.
The meter starts only when you press the button.
How accurate is it?
Not very, until you calibrate it. Phone and laptop microphones, and the processing behind them, vary from model to model. This meter asks the browser to switch off echo cancellation, noise suppression and automatic gain, filters the signal with the standard A-weighting curve and averages it the way a sound level meter does (fast 125 ms, slow 1 s). It then assumes a full-scale signal equals 100 dB SPL, a rough middle for consumer microphones. Expect errors of 10 dB or more without calibration, and readings that top out wherever your microphone clips.
Calibrate
The offset is saved only in this browser. For legal, workplace or medical decisions use a certified (IEC 61672 class 1 or 2) meter.
Read more: how phone decibel meters work and how accurate they are.