Like title says it will be really nice an helpfull to associate a sound when you reach and X% of your full hp. So you can concentrate your attention on your gameplay without looking everething 3-5 seconds on your hp bar. It will make the game more confortable and more sophisticated
Something like Zelda but without keeping the sound all the time, just one reproduction without repeat on
ps. Sorry for my bad english , i hope you understand my idea.