Sound Mimicry – The character has a body composed of sound. Sound Mimicry is also known as Audio Mimicry, Noise Mimicry, Noise Physiology, Sonic Mimicry, Sonic Physiology, Sonokinetic Form and Sound Physiology.
Klaw (Marvel) decided to become pure sound in Fantastic Four V1 #56.
Klaw is sliced into pieces by Doctor Doom and he feels no pain in Secret War I #9.
Music Master is probably the first character that can become sound in Heroic #12 (Eastern Color).