  We give a new interpretation of the effect of initial state entanglement on
the spectrum of vacuum fluctuations. We consider an initially entangled state
between two free massive scalar fields in de Sitter space. We construct the
initial state by making use of a Bogoliubov transformation between the
Bunch-Davies vacuum and a four mode squeezed state, and then derive the exact
power spectrum for one of the scalar fields. We demonstrate that an oscillatory
spectrum hardly appears for the initially entangled state unless an ad hoc
absolute value of the Bogoliubov coefficients is chosen.
