Originally Posted by gap

Since the object particle that the sound is linked to is not supposed to be visual, we might try placing it in the same ParticleGenerator as the visual bitmap particle, as an array item.

I have also noticed that increasing the max number of particles makes the effect somehow smoother. My suspect is that the total count of particles spawned must be multiplied by the number of times the particle generator is linked to the object (8 times in our case).