If I understand correctly, you want to "apply" the simulation where there are peaks in the curve, correct ?
You already have a line with the correct animation applied to it. Doesn't that look like a ramp already ?..
What I would do is sample directly from the line instead of using chramp. (This code requires the "channel_audio_import" node to be the third input of your wrangle)
float end = 50.0;
float frame = (@Frame + v@P.z*10) % end ;
float pos = fit(frame , 1, end, 0.0, 1.0);
pos = chramp("AnimCurve", pos);
// These two lines are the only difference
float sample = 1 - relbbox(0, @P).z; // You can visualize this with "v@Cd = sample;". A 0 to 1 value in the relative bounding box.
pos = primuv(2, "audio", 0, set(sample, 0, 0)); // Sample the audio attribute of the line based on sample
v@P = primuv(1, "P", @ptnum, set(pos, 0, 0));
[...] // rest of the code is untouched
Now, the result might not be what you expected. This clamps when "audio" is higher than 1, so you might want to do some post-process on the audio.
Hopefully that's what you want !
P.S. I found that reducing the amount of points in the line yields a better result, you might want to try that (50 points instead of 498).
Try it to see if you like that.