a supernova would eject enough matter to create a significant noise.
according to some less-that-trustworthy-sources, a kilogram of tnt, which is about 1MJ, prodces 90 db of noise at 5 meters. a normal/small sized supernova, which unleases about 10e44J of energy, 10e38 times louder than the kilogram of tnt, assuming the amount of sound is proportional. so the sound from a supernova is 490 db at 1m, 430 db at 1km, and about 269 db at 1AU. by the way, 200db is enough to cause instant death.
At farther distances than this, the volume drops off significantly as the density of the medium is much lower. however, assuming the density stays the same, you would be able to hear supernova's up to 50 megaparsecs away. thats incredibly far, about 1% to the edge of the observable universe.
@dar i don't see exactly how that could be done, but there could be two points of mass in any body, one at each focus in the ellipsoid.