Android: Amplitude value for decibel value?

Question

I am trying to restore the decibel of noise from the microphone on an Android phone. I can get the value of the amplitude and look for a formula to convert it to decibels.

I use the following MediaRecorder function to get the amplitude.

mediaRecorder.getMaxAmplitude ();

In another question, I found the following formula.

power_db = 20 * log10 (amp / amp_ref);

amp is amplitude, but not sure amp_ref .

Does anyone know the correct formula?

Answer 1

I think this is the right formula. amp_ref - reference amplitude