This app is a tool to measure sound (noise) level around you. It is using your built-in microphone. It should be called as a SPL(sound pressure level) meter, that is not related to frequencies like dB(A) and dB(C).
※ How to use it ???
- Just open the app, and read the number.
- If you want to save the data, get the screenshot. Click the camera icon on the app bar.
※ Introduction video
※ Examples of sound pressure
20dB : Rustling leaves, Ticking watch
30dB : Quiet whisper at 3 ft, Library
40dB : Quiet residential area, Park
50dB : Quiet office, Quiet street
60dB : Normal conversation at 3 ft
70dB : Busy traffic, phone ringtone
80dB : Busy street, alarm clock
90dB : Factory machinery at 3 ft
100dB : Subway train, Heavy snoring(2ft)
110dB : Rock music, Screaming child
120dB : Threshold of pain, Thunderclap
130dB : Jet engine at 100 ft
180dB : Space shuttle lift-off
② Screen capture
③ Refresh : 3 red lines mean max, mean and min. To reset them, long-click on the center of meter or click the refresh icon.
④ Text / Chart toggle
⑤ Black / White toggle : make your screen dim for saving battery.
⑥ Play / Pause toggle
※ Don't blame the app for Maximum Limitation
Most microphones are aligned to human voice (300-3400Hz, 40-60dB). It is enough for voice calls. But it occurs an issue of 16 bits microphone limitation.
See sound pressure at calibrate menu. It'll stop at 32767 (32767=2^15-1). Briefly, 16 bits microphones cannot measure above 96 dB. (more link)
Because of additional optimization (background noise reduction), some devices can measure at most 80 dB. Galaxy S3-S5(81-84db), HTC Desire HD(85db), Galaxy Note(81/91db). Some Motorola and Amazon Fire devices can measure 96 dB fully.
Last year, a german user suggested a trick in order to bypass hardware limitation. Add +30dB at calibrate menu, and close your microphone hole with your finger, so that you can measure a sound over 100dB. Try it out. :)
※ How to calibrate it ???
In order to calibrate the app correctly, you must compare it with an ACTUAL sound level meter. Otherwise, ensure that the value is 30-35dB in a very quiet room. If the result were out of range, you could add/reduce the number with calibrate menu.
It is an auxiliary tool for reference. Just enjoy it.
Q. It says "Unable to open microphone.".
A. The other app occupies your microphone. Restart your device.
Q. Where is the screenshot stored ?
A. /storage/sdcard0/smart-tools/, /mnt/sdcard/smart-tools/, /storage/emulated/0/smart-tools/... Surely, you can find the screenshots in your Gallery.
Q. I could hear nothing. But it points out 30-40dB.
A. The microphones can catch very low-frequency noise. 0 dB means vaccum (no air).
Q. Is the result dBA weighted?
A. The app had been calibrated by a actual SPL meter with dBA. It can measure "sound pressure level", not related to frequencies.
Q. How to save the data?
A. Get the pro version. It can save charts and export CSV file for MS-Excel.
※ Pro version added features
1) Vibrometer is included
2) Statistic menu
3) Level notification
4) Line-chart duration
5) No ads
- v1.6.3 : Material design
- v1.6.2 : Galaxy S6 support
- v1.6.1 : Sound effect On/Off
- v1.6.0 : B/W and reset button
- v1.5 : Action Bar added
- v1.4 : Tablets support
- v1.3 : Line-chart added
- v1.2 : App2SD
- v1.1 : Mean value line
- v1.0 : Sound Meter released (Nov, 2010)
If you have any idea to improve it, feel free to contact me. firstname.lastname@example.org