Using ultrasonics, acoustic attenuation characteristics of Pd 40Cu30P20Ni10, Zr 65Pd12.5Ni10Al7.5Cu5, Cu55Zr30Ti10Pd5, and Ti 41.5Cu47.5Ni7.5Hf5Zr 2.5Sn1 glassy alloys were examined in comparison with crystalline metals based on complex viscoelasticity. The glassy alloys favor to absorb the longitudinal one, but crystalline materials absorb the shear one, associated with periodicity and randomness of energy potentials, respectively. In sharp contrast to crystalline materials, Nyquist [Bell Syst. Tech. J. 11, 126 (1932)] diagrams of the glassy alloys are characterized by large areas of the third and the fourth quadrant in the loop, suggesting advancement of the relay in phase, that is, increment of the imaginary parts in complex waves.