This Xpresso setup is called SoundFlop. It is hooked to MoGraph’s Sound Effector. SoundFlop counts every hit that goes over certain threshold. I’m a bit confused how Sound Effector doesn’t have this feature out of the box. Fortunately we can fix this unfairness with simple Xpresso rig.
Threshold can be controlled with Sound Effector’s parameters, like “lower cutoff”, “compression” and “filter shape”.
Notice that the sound effector requires a wav file!