CH 01 · Audio
Decibel meter
Use this decibel meter to check the sound level picked up by your device’s microphone. Start the test and view A-weighted readings; nothing leaves your device.
Approximate: relative to your microphone, may be off by 20 dB or more
- Now
- –dB(A)
- Average (Leq)
- –dB(A)
- Min
- –dB(A)
- Max
- –dB(A)
- Against full scale
- –dBFS(A)
Calibration offset0.0 dB
To make the number trustworthy, hold a sound level meter next to your device, type what it shows and press Match it. The offset stays in the address of this page.
Typical levels, with sources (18)
- Whispering
Listen Up! Protect Your Hearing30 dB - Bedrooms during the night
Noise (fact sheet)30 dBA - Classrooms
Noise (fact sheet)35 dBA - The sound of your fridge humming
Listen Up! Protect Your Hearing40 dB - Annual average (Lnight) outside of bedrooms
Noise (fact sheet)40 dBA - The sound of your dishwasher running
Listen Up! Protect Your Hearing45-65 dB - Your normal talking voice at arm's length
Listen Up! Protect Your Hearing65-80 dB - A movie theater
Listen Up! Protect Your Hearing70-104 dB - Lawn mower
Listen Up! Protect Your Hearing80-100 dB - Motorcycles
Listen Up! Protect Your Hearing80-110 dB - Printing presses, lawn mowers, vacuums, power tools
Noise-Induced Hearing Loss85-90 dBA - NIOSH recommended exposure limit (over 8 hours)
Noise-Induced Hearing Loss85 dBA - Sports events (like a football or hockey game)
Listen Up! Protect Your Hearing94-110 dB - Rock concerts, parties, or nightclubs
Listen Up! Protect Your Hearing95-115 dB - Bulldozers, ambulance sirens, chain saws, bars/nightclubs, large sporting events (average)
Noise-Induced Hearing Loss95+ dBA - Listening to music with your headphones at the highest volume
Listen Up! Protect Your Hearing96-110 dB - Sirens from a fire truck, police car, or ambulance
Listen Up! Protect Your Hearing110-129 dB - Firecrackers and fireworks
Listen Up! Protect Your Hearing140-160 dB
Levels as their sources print them: the CDC page uses dB, NIOSH and WHO use dBA. The highlighted row is the nearest below your reading.
What this decibel meter measures
The test listens to raw input from your device’s microphone and applies an A-weighting filter. This filter follows the IEC 61672 curve, which the tool checks against its table at standard frequencies. The displayed level is shaped by this filter before the tool calculates its readings.
Fast weighting responds over 125 ms, while slow weighting responds over 1 s. These settings change how quickly the displayed level follows changes in sound. They do not change the sound around you, and they do not make the microphone a calibrated sound meter.
Without calibration, the reading is relative to the microphone’s full scale. The page gives an approximate dB(A) value and explains how far it can be off. Microphones differ, so treat this value as an estimate rather than an exact sound pressure level.
Readings and sound examples
The live A-weighted level shows the current filtered sound reading. Fast weighting follows changes more quickly; slow weighting smooths changes over a longer interval. Compare both to see whether the sound level is steady or changing.
Minimum and maximum show the lowest and highest levels recorded during the test. Average, also called Leq, summarizes the measured level over time. These readings depend on the period you measure, so keep that in mind when comparing them.
The page also shows typical noise levels with their sources. Use these examples to put a reading in context, not as a pass or fail limit. If you add a calibration offset from a known source or a meter, the page applies it to the readings; the offset is kept in the query.
When a reading looks wrong
A reading that stays at zero, does not change, or seems far from the sound you expect may mean the microphone is not available, its input is too low, or its response differs from a calibrated meter. A loud or quiet result by itself does not show that the device is broken.
Check whether the microphone is available to the page and whether sound is reaching it. If the test cannot read the microphone, use the page’s microphone not working fix guide. If readings continue to seem off, compare them with a known source or meter and use a calibration offset; calibration can adjust the displayed level but does not change the microphone.
Using the test well
Place the device where it can pick up the sound you want to check, then start the test and watch the live level. Let the reading run long enough to include the sound you care about. Switch between fast and slow weighting to see quick changes and steadier levels.
Use minimum, maximum and average to describe what happened during that measurement. For a comparison, keep the device and its position consistent and use the same weighting and calibration offset. The test is for checking sound levels, not hearing or health.
Browser support
| Browser | Runs |
|---|---|
| Chrome and Edge on a computer | Yes |
| Firefox on a computer | Yes |
| Safari on a Mac | Yes |
| Safari on iPhone | Yes |
| Safari on iPad | Yes |
| Chrome on Android | Yes |
| Samsung Internet | Yes |
| Browsers inside apps | PartlyMany apps block the camera and mic here: open the page in your browser. |
Source: MDN browser-compat-data 8.1.8 · checked November 6, 2026
Questions
How accurate is this decibel meter?
Without calibration, it reports a level relative to the microphone’s full scale and gives an approximate dB(A) reading. The page explains how far off it can be. Microphone sensitivity and response affect the result.
What is the difference between fast and slow?
Fast weighting uses a 125 ms response, so the reading follows changes more quickly. Slow weighting uses 1 s and smooths changes over a longer interval. Choose based on whether you want to see quick fluctuations or a steadier level.
What do minimum, maximum and average mean?
Minimum and maximum are the lowest and highest readings recorded during the test. Average, or Leq, summarizes the measured level over time. The period you measure affects all three.
How do I calibrate the reading?
Use a calibration offset from a known source or a meter. The offset adjusts the displayed level, and the page keeps it in the query. Without calibration, treat the dB(A) value as approximate.
Why does the reading not match what I hear?
The microphone may have a different sensitivity or response, and an uncalibrated reading can be off. The test also measures sound at the device’s microphone, so its position affects what it picks up. Compare with a known source or meter if you need a reference.
What should I do if the microphone reading is stuck?
The microphone may not be available to the page or may not be picking up sound. Open the page’s microphone not working fix guide for help. A stuck or unexpected reading alone does not establish that the device is broken.