Shape of the P-wave

Another question I've wondered about. If we define the P-wave shape as a graph with time on the X axis and intensity on the Y axis, what kind of rising edge, peak and trailing edge do you experience? On insertion I get an immediate rapid rise to a medium level, it levels for about 20 seconds, then ramps down. During a typical session though I'm riding low-medium all the time then get sudden spikes to high and intense plateaus, hang there for as much as a few minutes (with all that shaking and wiggling stuff going on), then fade off fairly quickly to that medium level until the next one rolls around. The peaks are often sudden with sharp impact, like someone punching me in the stomach. They can be surprising at first, then of course most welcome.

Anyone else care to share their wave shape?