Grunts, gurgles, wails, guttural belches, shrieks, screams, vomits, wretches, barks, growls ... ah, you get the point — just don't call them "Cookie Monster vocals."

This is the list where we celebrate metal's non-traditional singers, those who have perfected various techniques that opened a portal to new sonic dimensions within the metal-verse. If you've ever practiced these styles, then you know how difficult and painful of a process it can be to master. No, it isn't "just screaming." Doing it the wrong way can damage your voice and strain your vocal chords, certainly something that must be avoided when sustaining a career in a sea of extreme metal sub-genres.

There's no one vocalist to trace the true origins of this vocal style back to, but Lemmy's influence is the most obvious as to how we got to the focal point of this list. His gritty, whiskey-soaked attack inspired frontmen from first wave black metal battalions like Venom's Cronos, Hellhammer's Tom G. Warrior ... and the list goes on.

As metal became heavier, it required something beyond falsetto screeches and booming operatic bravado. Thrash was quick to adopt a harsher vocal style, more rhythmic in it's approach, dropping to mid-range. When death metal spawned from thrash's most aggressive moments, the vocals got lower along with the tunings and a more extreme style was necessary to convincingly convey more morbid themes. Black metal's lo-fi assault called for something else as abrasive higher shrieks and gravelly wretches fell in line with the incessant tremolo picking and almost non-existent production values.

Of course these aren't the only two styles that utilize vocal extremity and we're set to explore more styles and the representatives who have done it the best throughout the decades. Scroll through the gallery below as we count down the Top 25 Extreme Metal Vocalists.

Top 25 Extreme Metal Vocalists