Musical Aspects of Vowel Formants in the Extreme Metal Voice

In place of the pitched singing found in most genres of Western popular music, extreme metal vocalists use specialized screaming techniques that emphasize timbres associated with aggression, anger, power, alarm, and other emotionally charged utterances. Largely because these techniques resist established methods of music analysis, scholarly writings on heavy metal music have not yet acknowledged several of the most important acoustical and expressive features of the extreme metal voice. Using spectrograms generated with AudioSculpt, a powerful sound analysis, processing, and re-synthesis program, this paper argues that the acoustical properties of vowel formants serve a primary expressive role in enhancing the uncanny timbral qualities of extreme metal vocals.

We begin from the performer’s perspective, addressing the physiological mechanisms involved in the production of extreme metal vocals as well as their primary acoustical characteristics. Because, as we argue, the formant frequencies of vowels are amongst the most important—and under-researched—of these, we demonstrate in two separate contexts how vocalists have sacrificed the intelligibility of their lyrics by expressively altering their vowels. Finally, to demonstrate further expressive resources used by extreme metal vocalists, we show how rapid and large fluctuations in a first formant frequency envelope support arguments made by Williams and Stevens (1972) on the acoustical correlates of emotions and speech.