How to turn off the trackball sounds on a BlackBerry Pearl 8100, 8110, 8120 or 8130.
1. From the Home screen, press Menu.
2. Click Options.
3. Click Screen/Keyboard.
4. Set Audible Roll to Mute.
5. Press Menu.
6. Click Save.
Now you won’t be annoyed with the sounds of the trackball anymore.