Have you noticed that Facebook has started making a lot more noise lately? Facebook is rolling out a new alert system to users that plays a sound when you receive a new notification. If you have a browser tab open, even in the background, a sound will play.
Note: This update only affects users that visit Facebook.com in a browser.
You can turn this off!
Visit your Account Settings by clicking on the gear image to the right of your name and photo at the top of the page. Click on the Notification Settings on the left. “How You Get Notifications” should be the first group of settings that you see:

Click the “View” link to the right of “On Facebook” to expand the settings options.

By default, the “Play a sound” option is checked. Uncheck the box and click ”Save Changes.” You’ll then be free of a little extra noise pollution; at least until the next sound alert rolls out.
