  We provide the first evidence that the puzzling dielectric Debye process
observed in mono-alcohols is coupled to density fluctuations. The results open
up for an explanation of the Debye process within the framework of conventional
liquid-state theory. The spectral shape of dynamical bulk modulus of
2-ethyl-1-hexanol is nearly identical to that of the shear modulus, and thus
the supramolecular structures believed to be responsible for the slow
dielectric Debye process are manifested in the bulk modulus in the same way as
in the shear modulus.
