Validate your measurements
Repeat the same measurement under the same conditions to see whether a browser tool tracks sound consistently.
What validation means here
A check you can repeat and document.
For Decibel Meter Lab, validation means checking repeatability and relative tracking: do similar conditions give similar readings, and does the reading move in the expected direction when you change one thing?
It does not establish an accurate absolute sound pressure level. Different devices, microphones, operating systems and browsers may produce different absolute readings for the same sound. Keep the setup fixed when comparing runs; see Accuracy & Limitations for the reasons readings vary and Methodology for how the browser calculates them.
Simple Validation Protocol
Use one setup for a set of runs, then change only one variable.
Record the setup
Write down the device, browser, operating system, selected microphone, and any calibration or alignment offset. Note the date, room, and source.
Choose a steady source
Use a stable 1 kHz tone, pink noise, or steady fan noise. Keep its playback volume or operating setting fixed, and avoid levels that are uncomfortable or cause clipping.
Fix the positions and room
Keep the distance, microphone height and orientation, and source position the same. Leave the microphone uncovered. Keep doors, windows, background noise, and other room conditions as consistent as possible.
Run repeated sessions
Start the Decibel Meter, let the reading settle, then run at least three separate 30–60 second measurements. Stop and restart the meter between runs so each session has its own Min, Avg, and Max.
Compare and record
Log each run’s duration and displayed Min, Avg, and Max. Similar averages under unchanged conditions support repeatability; note any drift, peaks, or interruptions. These displayed summaries are not professional time-weighted or Leq measurements.
Change one variable
To check relative tracking, change only one factor, such as source volume or distance, and repeat the runs. Record exactly what changed. If a calibrated reference meter is available, compare it beside the device under the same steady conditions and record its reading and any alignment offset used. An offset applies to that setup; it does not certify the browser.
Example results log
Illustrative values only. Record your own readings for each run.
Example setup: laptop, Chrome, Windows, built-in microphone; steady fan at a marked distance of 1 m; same room and microphone orientation; default alignment (no user offset); calibrated reference meter unavailable. If you apply an alignment offset, record its signed value here, such as +2.0 dB.
| Run | Duration | Min | Avg | Max | Conditions / notes |
|---|---|---|---|---|---|
| 1 | 45 s | 58.4 | 61.7 | 64.2 | Fan steady |
| 2 | 45 s | 58.1 | 61.5 | 64.0 | Same setup |
| 3 | 45 s | 58.6 | 61.9 | 64.4 | Same setup |
For a changed condition, start a new set of runs and label the one variable you changed. Record a calibrated reference meter’s result in your notes when available; compare it under the same conditions and keep the offset with the device and browser details.
These numbers illustrate how to log a repeatability check. They are not a pass threshold or evidence of absolute accuracy.