Deathroll sounds do not stay with ships for the purposes of positional sound.

In FS2, the "Deathroll" sound, the sputtering engine sound that ships make before they explode, do not follow the ship as it explodes. They instead stay at the position where the ship first reached 0 hitpoints.

This does not appear to be intended behaviour, as the deathroll sound stops when the ship explodes (and as such is tied to the ship otherwise). It's most notable when shooting a fighter that moves from left to right or right to left. If a missile hits it on your right, the ship will move across your vision, but the deathroll sound will stay in place.