  This paper was initiated by publication of Ref. [1] and can be considered as
Comments on Ref. [1]. Authors of Ref. [1] investigate analytically the
propagation of sound waves in one component monatomic gas (especially for the
intermediate Knudses number region) using methods of local kinetic description
in area where they are not applied in principal.
  [1] Napier D.G., Shizgal B.D. Sound Dispersion in Single-Component Systems.
Physica A 387, 4099--4118 (2008)
