  We investigate several means of coupling between a sonoluminescing bubble and
an applied magnetic field. Recent experiments show a strong quadratic
dependence between the forcing pressures required for stable sonoluminescence
and magnetic field amplitude. However, all coupling mechanisms calculated here
for comparable magnetic fields involve energies no more than one percent the
mechanical energy of bubble collapse. We conclude that the applied field must
influence the system though its effect on some parameter which the bubble
motion depends upon very sensitively. A few such mechanisms are suggested.
