Google shocked their users in both a good and bad way this past Friday with the Pac Man Google Doodle for the 30th anniversary of the game. Google received so much feedback on the interactive game Doodle that they decided to keep it live at google.com/pacman.
The bad feedback was mostly around the noise of the game. People, many of them, didn't like it, and wanted a way to turn it off. Google at some point totally killed the sound but then brought the sound back with a mute button. Here is a picture of the mute button, which was not part of the game's interface by the way.
I should note that Mike from my team built a way to embed the Pac Man Google Doodle on your own web site. Which I did over here. Our version doesn't have sound.
Another thread asks if there is a way to always opt out of Google Doodles. Some people just want to see the Google logo as is and never see the special Doodles. Currently there is no way to go to Google.com, without a browser plugin, and guarantee you never see the Google Doodles. Maybe Google can add that?
Forum discussion at Google Web Search Help & Google Webmaster Help.