  In a recent article M. Baggioli and A. Zaccone (Phys. Rev. Lett. {\bf 112},
145501 (2019)) claimed that an anharmonic damping, leading to a sound
attenuation proportional to $\omega^2$ (Akhiezer-type damping) would imply a
boson peak, i.e.\ a maximum in the vibrational density of states, divided by
the frequency squared (reduced density of states). This would apply both to
glasses and crystals.Here we show that this is not the case. In a
mathematically correct treatment of the model the reduced density of states
monotonously decreases, i.e.\ there is no boson peak. We further show that the
formula for the would-be boson peak, presented by the authors, corresponds to a
very short one-dimensional damped oscillator system. The peaks they show
correspond to resonances, which vanish in the thermodynamic limit.
