  Comprehending sound damping is integral to understanding the anomalous low
temperature properties of glasses. After decades of theoretical and
experimental studies, Rayleigh scattering scaling of the sound attenuation
coefficient with frequency, $\Gamma \sim \omega^{d+1}$, became generally
accepted when quantum and finite temperature effects can be neglected. Rayleigh
scaling invokes a picture of scattering from defects. However, it is unclear
how to define glass defects, or even if defects are necessary for Rayleigh
scaling. Here we determine a particle level contribution to sound damping in
the Rayleigh scaling regime. We find that there are areas in the glass that
contribute more to sound damping than other areas over a range of frequencies,
which allows us to define defects. We show that over a range of glass
stability, sound damping scales linearly with the fraction of particles in the
defects. However, sound is still attenuated in ultra-stable glasses where no
defects are identified. We show that sound damping in these glasses is due to
nearly uniformly distributed non-affine, microscopic forces that arise after
macroscopic deformations of non-centrosymetric structures. To fully understand
sound attenuation in glasses one has to consider contributions from defects and
a defect-free background, which represents a new paradigm of sound damping in
glasses.
