Android：如何将getMaxAmplitude转换为db？

I have a piece of code that give me the getMaxAmplitude() of the audio from the mic. it works, but the value is surely strange. i need to convert it to decibel. how can i? i've found this formula: double db = 20 * Math.log10(recorder.getMaxAmplitude() / 2700.0); but i don't know if it's correct. thanks.I have a piece of code that give me the getMaxA