Have you ever experienced that annoying sound when you enter a web page? Probably not just once. But, there's a solution waiting for you to apply!
If you use Google Chrome, go to chrome://chrome/settings/content and in a section "Plug-ins" check option "Click to play". The flash content will be run only if you click on it. Additionally click "Manage exceptions..." and add domains for which you want to allow/deny flash (e.g. www.youtube.com).
Now you can browse in peace ;-)
