noise_meter 5.0.2 - documentation about the "Conversion to Decibel"

**noise_meter 5.0.2 - documentation about the "Conversion to Decibel"**

### Description
I am not able to get the conversion formula, what the formula expect,
Does it expect integer value or float value, earlier in microphone data it is explained that float value is from 1 to -1 and it is derived from pcmValue by dividing the max integer value.

I think the formula should be as follow

db = 20 * log10(pcmValue / 2**15)

in case of pcmValue is of 2 bytes integer

### Additional information
Add any other info about the problem here.