Distortion effects compress the peaks of sound waves and add overtones to create warm, dirty, and fuzzy sounds as demonstrated in the song "All Around the World" by Red Hot Chili Peppers. Reverberation or reverb is created when sound echoes in an enclosed space and decays slowly, heard in the song "Guilt" by Nero. A phaser filters a signal by creating modulated peaks and troughs, producing a sweeping effect showcased in Pink Floyd's "Another Brick in the Wall".