A lot of the concepts in this article appear to be deliberately simplified and terminology deliberately abused, and I would argue too much so. Take this paragraph for instance:
> As you look at the waveform, the problem should become apparent. Sound is a 3-dimensional construct, but we can only represent 2 dimensions on a textbook or a monitor. In the waveform representation, we see Time on the x-axis plotted against Volume on the y-axis.
The two axes in most waveform plots are sound pressure and time, not volume and time. The fact that the waveform depicted is nearly symmetrical reflected across the x axis should hint that this is the case.
> As you look at the waveform, the problem should become apparent. Sound is a 3-dimensional construct, but we can only represent 2 dimensions on a textbook or a monitor. In the waveform representation, we see Time on the x-axis plotted against Volume on the y-axis.
The two axes in most waveform plots are sound pressure and time, not volume and time. The fact that the waveform depicted is nearly symmetrical reflected across the x axis should hint that this is the case.