By default when you use the volume keys on your Mac’s keyboard to adjust its volume, a neat little “blip” sound is heard in order to give you a sense of how loud its speakers are. It’s definitely a handy feature, but sometimes you just don’t want to hear it.
A perfect example is when listening to music or watching a movie, especially when you’re hooked up to some loud, external speakers. You’re already getting feedback from the content playing, so that blip sound will just be loud and annoying.
Sound Preferences in Mavericks
To suppress the feedback sound when changing your Mac’s volume using the volume up/down keys on your keyboard, simply hold the Shift key as you press the volume keys. However, you can also invert this behavior and only hear feedback when holding shift. Simply open System Preferences, head to the Sound Preference Pane, and uncheck the box for “Play feedback when volume is changed.”
Now whenever you use the volume keys on your keyboard, you’ll no longer hear audio feedback unless you press the Shift key at the same time. Pretty cool, eh?