I Love this little utility app - I've used it for 6 years on a G4 Powerbook, a G4 Digital Audio, a MDD G4, and a G5 dual 2.0 (all running Tiger 10.4.11). Also worked on the G5 & the Powerbook under Leopard 10.5.6.
After years of "too loud" startup chimes waking the kids at 3 AM [and freaking ME out as well!], I finally have the perfect solution! The app is 'persistent', so set it and forget it! (unless you want to make changes, then just relaunch & move the slider volume). One of my all-time favorite apps!! Does EXACTLY what it needs to, and DOESN'T mess with anything else! I've never had any app or sys process conflict with it.