The optical transmission modulation observed in the presence of acoustoelectric domains has been investigated in CdS and compared with the light scattering from the acoustic flux. Calculations of the decrease in the optical transmission due to light scattering show that light scattering may account for all the transmission modulation observed in the presence of acoustoelectric domains. The existing arguments for the presence of high ac-electric fields connected with the domains are discussed, and it is concluded that these arguments probably are not correct. [Russian Text Ignored].