How to measure sound levels
- Press Start the sound meter and allow the microphone.
- Watch the live level, the minimum, maximum and average, and the graph of the last minute. Pick Fast or Slow response.
- To read approximate dB instead of dBFS, enter a calibration offset: the difference between this meter and a real sound level meter in the same place.
How the meter works
The meter turns off the browser’s echo cancelling, noise suppression and automatic gain, which would otherwise change the level. It then measures the average power of the sound, smoothed with the Fast (0.125 s) or Slow (1 s) time weighting used by sound level meters, and shows it in decibels.
Next to the live reading you get the minimum and maximum since you started, the average over the whole time (the equivalent continuous level, Leq) and a graph of the last 60 seconds. Reset min and max starts those figures afresh.
Why phones aren’t sound level meters
A real sound level meter has a measurement microphone calibrated to a known pressure, so it can report dB SPL directly. A phone or laptop microphone is built for voices, often boosts or cuts some frequencies, and may clip on loud sounds. The operating system can apply its own processing too. That’s why this meter shows a relative level by default and lets you add your own calibration offset, rather than claiming an exact number.
Use it to compare: is the fridge louder than the fan, did the new window make the room quieter, is the music louder than before? For anything that matters, such as workplace noise or a complaint, use a calibrated meter.