  We evaluate the sound attenuation in a Weyl semimetal subject to a magnetic
field or a pseudomagnetic field associated with a strain. Due to the interplay
of intra- and inter-node scattering processes as well as screening, the fields
generically reduce the sound absorption. A nontrivial dependence on the
relative direction of the magnetic field and the sound wave vector, i.e., the
magnetic sound dichroism, can occur in materials with nonsymmetric Weyl nodes
(e.g., different Fermi velocities and/or relaxation times). It is found that
the sound dichroism in Weyl materials can also be activated by an external
strain-induced pseudomagnetic field. In view of the dependence on the field
direction, the dichroism may lead to a weak enhancement of the sound
attenuation compared with its value at vanishing fields.
