Sound propagation in a Fermi gas near a Feshbach resonance
  Sound waves are observed and studied in an optically trapped degenerate Fermi gas of spin-up and spin-down atoms with magnetically tunable interactions. Measurements are made throughout the crossover region, from a weakly-interacting Fermi gas through the resonant Fermi superfluid regime to a Bose condensate of dimer molecules. The measured sound velocities test the equation of state and confirm the universal hypothesis. 
J. Joseph, B. Clancy, L. Luo, J. Kinast, A. Turlapov, and J. E. Thomas