[FREE APP] [SOUND METER], A sound meter is a device that can measure level of noise or sound Pressure. Now you can have this app on your Android mobiles.

Description
Microphones in Android devices are made to record human voice, therefore the maximum noise is limited and very loud sounds cannot be recognized (in most cases above 100dB).
SPL(sound pressure level) meter uses your built-in microphone to measure noise volume in decibels(db).
It is a professional sound meter for your Android. Sound Meter is also known as sound level meter, decibel meter (dB meter), noise meter, sound pressure level meter (SPL meter). Sound Meter uses your Android's microphone to measure levels of noise or sound pressure levels and displays measured data in dB (decibels) with reference to generally known noise or displays the noise data on easy to read graph.
Features:
■ direct reading in dB
■ 20 to 110dB (decibels) range
■ vibrating alert
■ classic analog look
■ 2 clock faces meter (White & Black)
■ Text statistics
■ Graph statistics
■ Snapshot
■ free
Levels of Noise In decibels (dB):
110 dB - Rock music, Screaming child
100 dB - Subway train, Blow dryer
90 dB - Factory machinery at 3 feet
80 dB - Busy street, Alarm clocks
70 dB - Busy traffic, Phone ringtone
60 dB - Normal conversation at 3 feet
50 dB - Quiet office, Quiet street
40 dB - Quiet redinstial Area, Park
30 dB - Quiet whisper at 3 feet, Library
20 dB - Rusting leaves, Ticking clock
NOTE:
Due to microphone limitations on different devices the meter range is different, usually the low end of the scale cannot be achieved because of the microphone noise and the upper end of the scale is limited by the microphone distortion on high levels.
For this app any one can visit:
play.google.com/store/apps/details?id=com.expressinc.soundmeter