Acoustic measurement on a smartphone depends on its microphone, operating-system audio processing and hardware. Calibration adjusts overall sensitivity, but does not turn a phone into a standards-compliant sound level meter.
1. What is being calibrated?
A sensitivity mismatch shifts the displayed levels in decibels. The app lets you adjust that offset using a reference. Calibration does not eliminate frequency-response errors, clipping, audio processing or self-noise.
2. Comparison with a reference instrument
- Use a sufficiently stable sound source and a suitable reference sound level meter.
- Position the smartphone and the reference microphone close together without acoustically obstructing one another.
- Select comparable indicators, such as LAeq measured over the same interval.
- Adjust sensitivity in Sound Analyzer App's calibration menu to align the displayed levels.
- Repeat at different levels and, when possible, with different sounds.
Important: this is an indicative comparison, not an accredited calibration. Agreement for one sound and level does not guarantee accuracy across all frequencies and levels.
3. Practical precautions
- Avoid direct wind and sounds that could overload the microphone.
- Keep a repeatable geometry away from nearby obstructions.
- Consider whether the operating system is applying automatic audio processing.
- Recheck calibration if you change devices.
4. What accuracy can be expected?
No universal accuracy specification applies to Android smartphones. Unless a particular device has been characterized, the results should be treated as indicative. Use suitable compliant instruments for regulatory measurements.