Yes, it would be done inside a space station or spacecraft of some kind. The reason that this is more attractive in space is that the forces you can generate with acoustic levitation are small. You can only levitate very light objects (foam balls, ping pong balls, etc) against the force of gravity. In a microgravity environment you could use it to do containerless processing of metal, for example.
for additional reading: http://archive.org/stream/nasa_techdoc_19970021191/19970021191_djvu.txt
