Comment on "Energy Velocity of Diffusing Waves in Strongly Scattering Media"

A comment on the recently published article (PRL 79, 3166 (1997)) is given. The issue is if there is a unique self-consistent way in determining the effective medium in a random medium. The recently introduced effective medium theory (PRL 75, 3442 (1995)) based on the principle of energy density homogenization is also discussed.