In "And the Award for Sound Design Goes to Rob", Raven was getting annoyed with all of the noise the other Titans were making. The Whisper came to Raven's room and told her that she could make all of the sounds go away if she tickled her belly. It was difficult for Raven to hear The Whisper at first because, on top of all the noise, The Whisper only spoke in soft, gentle whispers. When Raven finally did hear The Whisper, she tickled her belly just like she asked, causing her to pop a box out of her belly. The Whisper opened the box, which engulfed all of the sounds in the universe, making everything permanently silent.
The next day, the other Titans started freaking out over all of the sounds missing and Raven started to regret her decision. The Whisper showed up and made fun of their silence, by playing an old-timey piano. Raven asked The Whisper to give her sound back, but she refused, saying that this was her evil plan all along. Rid the world of sound so that she could be the loudest thing in the universe. Raven tricked The Whisper into casting her spell so that at least they could get their own voices back. The Whisper didn't mind this as long as the rest of the world was completely silent.
The Titans found out that they could bring sound to inanimate objects while making noises with their mouths, which would cause the objects to start automatically making that noise on their own. They did this for many different objects.
The Teen Titans tracked down The Whisper to her evil lair on a giant mountain and challenged her to a battle. They warned her that they gave annoying sounds to many lots of regular objects, that were worse than their original sounds but The Whisper said that this would only convince the people of the world not to activate those noises. The Titans challenged The Whisper to a battle and they started making as much obnoxious noises and possible both with their mouths and with the inanimate objects. The Whisper got so annoyed with this, that she gave up and gave the magic box back to Raven, allowing for her to open it and bring the regular sounds back to the world again.