SPL(sound pressure level) meter app uses your phone mic to measure noise volume in decibels(db), and shows a reference.
We had calibrated many android devices with the actual sound level meter with dB(A).
REMEMBER!! The smart phone microphones were aligned to human voice (300-3400Hz, 40-60dB).
Therefore the maximum values are LIMITED by the manufacturers and the very loud sound(100+ db) cannot be recognized.
Galaxy S3(max.81dB), Galaxy Note(91dB), Galaxy S2(98dB), Moto Droid(100dB), HTC Desire(82dB)...
Vibrometer app uses the phone sensors to measure vibration or the earthquake, and it shows a reference as a seism detector.
The measured values are the Modified Mercalli Intensity scale(MMI), and just for reference.
If it is inaccurate, you can calibrate it so that the maximum value is about 10-11.
* Pro version added Features:
- Sound Meter and Vibrometer are integrated
- Statistic menu and Save log data
- Level notification
- Line-chart duration
- More models are calibrated
- No ads
- v2.4.2 : more models calibrated.
- v2.4.1 : 2nd-gen Nexus 7 support.
- v2.4.0 : ActionBar added. 7' Tablet PC fix.
- v2.3.3 : Nexus 10 and SGS4 support.
- v2.3.2 : Screen capture added.
- v2.3.1 : Nexus 7 support.
- v2.3.0 : Export to CSV file.
- v2.2.7 : Landscape mode for Tablet PC.
- v2.2.6 : more models calibrated.
- v2.2.5 : 4 hours line-chart duration.
Read Here: How to Install APK
Requirements: Android 2.0+
File Size: 1 MB
Download Link: Mediafire.com