Quick question about the music for the game ; I see you have already answered a few questions along those lines. When the bunny dies , there is a sound for its

Quick question about the music for the game ; I see you have already answered a few questions along those lines. When the bunny dies , there is a sound for its micro-explosion. I remember "Dangerous Dave" died with the same sound :) Are a lot of these interchangeably used ? Are these just system sounds ? How do these work ?