Figure 5 Driving effects. The time evolution of the potential can enhance the amplitude of the acoustic oscillation by driving effects. The first extrema here is suppressed due to the fact that the gravitation driving begins near sound horizon crossing. Notice that for the first cycle of the adiabatic and isocurvature oscillations, the gravitational force mimics a driving force of approximately twice the natural period. Figure 6 Heights of the peaks in a scale invariant adiabatic model.
Baryons increase compression in potential wells causing the peak heights to alternate.
Lower matter content causes more potential decay driving the oscillation.