Windows. is the operating system that most popular from microsoft which has many sound effect, such an error, exclamation, start, off, etc. Now you have to help me to "Re-enable" these sound bellow: -log off, -shutdown (already apply since 4.04 but discontinued since 8.04).
that's it! @Compaq510 @Ubuntu12.04 answer it with detail such editing .sh, or else as you can! other sound in 12.04 such critical stop, warning, etc. is just applied. some other hidden not. so Hidden sound is Bonus Mission! Good luck :D