问题
I found that some apps can display a decibel (dB) value for audio level. I have been trying for some time but have not been able to find the relationship between power and dB. Can anybody tell me how to do it ?
回答1:
You can use the formula:
dB = 10 * log10(power);
Note however that dB is a ratio, not an absolute measurement, so your dB values will be somewhat arbitrary unless you calibrate your system. The easiest solution is just to apply an empirically derived dB offset which gives you 0 dB = full scale.
来源：https://stackoverflow.com/questions/7845931/can-i-convert-peakpowerforchannel-to-db