Audio is a sequence of waveforms which have peaks, troughs, 0, just like below.
How to define the x axis (y = 0) in the picture, how to choose the 0 point in the waveform since there are so many points on the waveform?
Why not move the waveform above or below the x axis(y=0)?
This question seems a little stupid. But I still hope someone can help with it.