Veo en The Escapist el titular «Military Scientists Unveil Sound-Powered Fire Extinguisher» e inmediatamente me dirijo a la información original en Wired:

The sound increases air velocity, which then thins the area of the flame where combustion occurs, known as the flame boundary. Once the boundary area is thinned, the flame is easier to extinguish. At the same time, the acoustics are disturbing the pool of fuel and creating higher fuel vaporisation — this widens the flame, thinning it out so it is less concentrated and cool enough to extinguish. […] Even better, the sound does not even need to be offensively loud to achieve any of this.

Lo cierto es que los vídeos de demostración (uno [00m10s] y otro [00m27s]) no son tan espectaculares como imaginaba pero no dejan de ser interesantes para ver el efecto conseguido.