  Strongly interacting systems are characterized by heavily dressed entities
with internal degrees of freedom, which, on a local level, can be described in
terms of coherent quantum states. We examine the modification of these local
coherent quantum states when such entities condense into a macroscopic coherent
quantum state, such as superfluidity. As an example, we consider a system of
electrons coupled to local lattice deformations. Significant changes in the
phonon clouds surrounding the charge carriers occur when the system develops
into a spatially phase-locked state. The question of localized self-trapped
charge carriers (bipolarons) in the normal state becoming delocalized upon
entering the superconducting phase is discussed in terms of squeezing of the
local coherent phonon states. Suggestions for experimental verifications of
these features associated with the lattice dynamics are made.
