Android - How to disable startup and shutdown sound on Samsung Galaxy S?

In System -> Sound and Display -> System volume you can set it, unfortunately the power on/off sound is also tied to the touch feedback sound (ie you press a button, hear a sound). If that's not a problem, turn it all the way down and problem solved..

Try Silent Boot from the android market. It automatically mutes your phone when you shutdown.

In this post at Android Central, the suggestion is:

1. Open a root explorer, go to /system/media/audio/ui
2. Rename PowerOn.ogg to PowerOn.ogg.disabled, PowerOff.ogg to PowerOff.ogg.disabled

This requires root.

^{This seems promising, but in my HTC E9 phone (Android 5) these files don't exist :(}