Yuzool

Sound level meter

A sound level meter in your browser, with A-weighting and an offset to match a real meter.

–dB
Estimate: phone mics aren't calibrated
Tap Start to measure
20406080100120
Min–
Avg–
Max–
0:00
Last minuteOffset +100 dB
How loud is that?

Nothing is recorded: the page reads the microphone's level and keeps only the numbers. For a closer reading, set the offset against a real sound level meter in Settings.

About the sound level meter

A sound level meter measures sound pressure level in decibels. This one works like a simple handheld meter: A-weighted or flat (Z) readings, a live bar, and the minimum, maximum and energy average (Leq) over the time it has been running.

It is not a certified instrument. Certified meters (Class 1 and Class 2 under IEC 61672) use calibrated microphones; a phone or laptop microphone isn't, so the readings are estimates. If you can borrow a real meter, set the offset in Settings so this one reads the same.

Nothing is recorded: the page reads the microphone's level and keeps only the numbers. Works on phones and on computers with a microphone.

How to use it

  1. Tap Start and allow the microphone.
  2. Choose A-weighting (how loud it sounds to people) or Flat in Settings.
  3. Let it run through the period you care about; the average is an Leq, so short loud moments count for their energy.
  4. Tap Stop for a summary. Saving sessions with notes is part of Bubble Level Pro.

Good for

  • A rough check of a room's background noise
  • Comparing before and after soundproofing or a new fan
  • Showing a class or a team what different noise levels look like
  • Estimating levels before deciding whether you need a proper meter

Matching a real meter

Put this phone next to a real sound level meter, start both, and type what the real meter shows into Match a meter in Settings. The page works out an offset for this device so later readings line up more closely. Readings are still estimates: the microphone's response varies with pitch and direction, and some phones process sound before a web page sees it.

Questions

Can a phone be used as a sound level meter?

For an estimate, yes. For measurements that must stand up, such as workplace noise assessments, you need a calibrated Class 1 or Class 2 meter.

What is Leq?

The equivalent continuous sound level: the steady level that would have the same total sound energy as the changing noise over the same time. It is the average a sound level meter reports.

Should I use A-weighting or flat?

A-weighting for noise that people hear, which is how most limits and guidelines are given. Flat counts low rumble and high hiss at full strength.

More tools in Bubble Level

Bubble levelSpirit levelLevel appInclinometerAngle finderOnline rulerRuler on screencm rulerInch rulerProtractorCompassDecibel meterSound level meterNoise meter

Everything is in one free app: Bubble Level. Guide: How to hang a picture straight.