The Radiation of sound reference article from the English Wikipedia on 24-Jul-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)
Radiation of sound should not be confused with propagation of sound. Radiation is the process by which energy is transferred from one form, i.e. structural vibration, turbulent flow into a propagating acoustic wave. Succinctly, radiation of sound is caused by the transfer of momentum into the fluid medium.