Turning up or down the volume without disturb

Question

Is there a way to disable the disturbing icon and the clicking sound when I press F11 and F12 on the keyboard?  It's very annoying.

Answer 1

Arthur is right about the sound effect, but I actually found a way around the visual too.
I know this is a big post but I promise it's not too difficult!
You will need to download Quicksilver if you do not already have it as well as 3 Applescripts I wrote to do this very thing. The link to them is below.
In System Preferences, click "Keyboard" (second row, 4th item) and check the box to make the F keys standard function keys. This means you have to hold the Fn key to use them, but it is the only way to get around the popup volume icon.
If you want to, you can make Mission Control, Launchpad and Dashboard open from just the F key (so you do not need to hold Fn) if you go to Mission Control (first row, 4th item) and use the drop down boxes to set the buttons to do what you want. However, you will still have to hold Fn to change brightness.
Download these scripts and put them in a folder in your Applications folder. The folder name does not matter. I won't keep them in my dropbox forever, but I'll leave them up for a while in case anyone else wants them.
https://www.dropbox.com/sh/rtubl9rnqkthzby/ahqM--Ar6U
Keep the folder open, you'll need it in the next step.
Launch Quicksilver. Click Quicksilver at the top left of the screen then click Triggers. Make sure you can see the scripts beside the Triggers window. In the bottom left of that window, click the plus icon then Hotkey. Drag the Mute script into the top of the box where it says "Select an item." Do the same for the other 2 scripts.
Once they're all in, double click the Mute script under the "Trigger" column and press F10. Do the same for the others, making Down F11 and Up F12.
That should do it! Let me know if you have any questions or if something doesn't work, I'll be happy to help.