  In the background of a sufficiently strong magnetic field the vacuum was
suggested to become an ideal electric conductor (highly anisotropic
superconductor) due to an interplay between the strong and electromagnetic
forces. The superconducting ground state resembles an Abrikosov lattice state
in an ordinary type--II superconductor: it is an inhomogeneous structure made
of a (charged vector) quark-antiquark condensate pierced by vortices. In this
paper the acoustic (phonon) vibrational modes of the vortex lattice are studied
at zero temperature. Using an effective model based on a vector meson
dominance, we show that in the infrared limit the longitudinal (transverse)
acoustic vibrations of the vortex lattice possess a linear (quadratic)
dispersion relation corresponding to type I (type II) Nambu--Goldstone modes.
