  Careful re-examination of typical experimental data made it possible to show
that the UV continua observed in multi-bubble (MBSL) and single-bubble (SBSL)
sonoluminescence spectra have the same physical nature - radiative dissociation
of electronically excited hydrogen molecules [and probably hydrides of heavy
rare gases like ArH*] due to spontaneous transitions between bound and
repulsive electronic states. The proposed mechanism is able to explain all
available spectroscopic observations without any exotic hypothesis but in terms
usual for plasma spectroscopy.
