  The mechanism of acoustic wave propagation in supercooled liquids is not yet
fully understood since the vibrational dynamics of supercooled liquids are
strongly affected by their amorphous inherent structures. In this paper, the
acoustic wave propagation in a supercooled model liquid is studied by using
normal mode analysis. Due to the highly disordered inherent structure, a single
acoustic wave is decomposed into many normal modes in broad frequency range.
This causes the rapid decay of the acoustic wave and results in anomalous
wavenumber dependency of the dispersion relation and the rate of attenuation.
