  Plastic events in amorphous solids can be much more than just "shear
transformation zones" when the positional degrees of freedom are coupled
non-trivially to other degrees of freedom. Here we consider magnetic amorphous
solids where mechanical and magnetic degrees of freedom interact, leading to
rather complex plastic events whose nature must be disentangled. In this paper
we uncover the anatomy of the various contributions to some typical plastic
events. These plastic events are seen as Barkhausen Noise or other "serrated
noises". Using theoretical considerations we explain the observed statistics of
the various contributions to the considered plastic events. The richness of
contributions and their different characteristics imply that in general the
statistics of these "serrated noises" cannot be universal, but rather highly
dependent on the state of the system and on its microscopic interactions.
