In order to keep the sound of radio personality's voice sounding as good as possible, it's important to soundproof a radio studio.
Sound proofing takes the "hollow sound" out of a room. You know what it sounds like in your shower when you speak or sing? That effect is the sound waves bouncing off of smooth surfaces, like porcelain or tile.
Soundproofing is designed to take the bounce of the voice's sound wave when it hits the walls. Soundproofing flattens the sound wave. It does this by creating a special texture on the radio studios walls. Cloth and other designs on the wall are usually employed to flatten out the sound.