Android noise level detection and decibel calculation

Question

I have tried many examples of noise level detection from that some following examples I tried and debug:

• Detect noise or blow sound
• Android detect sound level
• Google SplMeter sample code

But I am get little bit confused on the following points:

• Difference between recording audio using Android MediaRecorder and AudioRecorder class (best settings to require good quality audio for both classes).
• How to calculate sound level into decibel using amplitude? (Please correct me if I am asking about wrong calculation or parameters)

Please share your ideas, documentation (that helps me to understand this concept), examples, tutorials, etc.

Answer 1

To calculate decibels you need a background reading. Decibels is the ratio of signal:noise, so you need to know what the background noise is. Once you have that, the formula is db= 10*log(signal/noise)