Once the sound becomes volts-hopefully accurately, an Analog to Digital converter creates a digital bitstream according to another dB range.

The job of the recordist is to put the mic where it will do the most good without breaking anything. You also can't get sound too low or the microphone won't generate any volts.

You can damage a microphone by subjecting it to loud noises. The microphone's job is to translate moving air into volts. That's where hearing loss can occur-ask any rock concert goer. There are average measurements published for 'Train Going By' and 'Airplane Going Over.' The system is open ended at least going up. So your ear works in the A curve and the microphones work in C. Fingernails on blackboard may make you hold your ears in pain whereas a light, but much more powerful earthquake (low rumble) will not. 'A' is biased to pay attention to the air movement the same way your ear does which is decidedly not flat. If the air moves with sound, the air moves. This is a measurement of the actual movement of air. The real world is measured in dBSPL or Sound Pressure Level. I suppose we should start with the differences between real world and digital recording.

The audacity meaning