“Blegh!” or “blech!” has become the trademark sound for metalcore. At this point, are you even considered a metalcore band if you don’t “blegh”? Probably not. It is the bringer of mosh. To quote the great Will Ferrell, “No one knows what it means, but it’s provocative. It gets the people going!”

The most prolific user of this sound effect is likely Architects. YouTuber Nick Trunov even diligently compiled every instance of this fantastically nasty noise by the band through 2017, sampled from songs such as “Gravedigger,” “Nihilist” and more. Other YouTubers, such as Core Enthusiast, have also compiled their own top “blegh” lists, featuring bands such as Wage War, Motionless In White and Lorna Shore.

On paper, “arf!” just conjures up thoughts of a toddler learning what noise a dog makes, but put a gruff touch on it and throw it in a metalcore or hardcore song and it’s a big hit. Preceding the first breakdown of the song “Counting Worms,” the dog bark is one of the rallying moments on Knocked Loose’s debut full-length, Laugh Tracks. (Watch it live.) The band Spite also kicks off their song “Leeches” with five arf’s in a row.

Pig squeals are strange screams used by a lot of deathcore and death metal bands, so-called because of their characteristic “breeee!” sound. The inhuman nature of the noise makes it pretty disturbing, which is why bands such as Despised Icon (“Oval Shaped Incisions”) and Job For A Cowboy (“The Rising Tide”) rely on it.

Hard rock band Disturbed has a set of strange sounds all their own. Vocalist David Draiman puts them on display in several of the band’s songs, but the most well-known is the hit single “Down With The Sickness.” It opens with the infamous “oo-ah-ah-ah-ah!” call, and continues with a sort of wretching sound (“uck, uck”). Draiman’s unique vocalizations in this song have earned it spots in a variety of movies and TV shows, including South Park.

Hardcore is a genre known for its fighting spirit. It’s also known for its blunt lyrical content, which is echoed by its no-frills aesthetic. One of the most frequently used tough-guy vocalizations is the short “oo,” which sounds like it’s supposed to accompany some kind of martial arts move. It’s the sound of throwing down. Find it in songs like “Nobody” by Stick To Your Guns and the heavily hardcore-influenced “Six Feet Under” by metalcore band Crystal Lake. The sound effect can also be found in some metal songs. Metal band Celtic Frost has a long history of using “oo” and other strange sounds on this list.

Evil or creepy laughter is a way for rock and metal bands of all subgenres to convey a sense of madness, or even just plain irreverence. From classic metal like Ozzy Osbourne’s “Crazy Train” to emo rock like The Used’s “The Bird And The Worm,” cackling adds a sense of twistedness that is oddly smile-inducing.

Yelping and shrieking was a common sound for classic rock and classic metal bands such as Van Halen and Judas Priest. “Runnin’ With The Devil” and “Painkiller,” respectively, are quintessential examples of these wild, high-pitched calls.

Black metal bands use a specific type of growling that is almost like croaking. It’s a long, droning, deathly vocal that sounds as though it’s coming from a reanimated corpse. Mayhem’s “Freezing Moon” with vocalist Attila Csihar is a good example of this style.

Gurgles happen at this weird intersection of black metal croaking and deathcore growling. It’s meant to sound demonic and otherworldly, but even for the most serious of fans, it’s really hard not to laugh. Dying Fetus may have some sick guitar shredding, but the incoherent gurgling at the 1:45 mark of “Praise the Lord,” for instance, is…befuddling.

Similar in use to “blegh,” “buh” or “ugh” appears in a lot of metal and metalcore songs as a way to include a scream without actually saying anything. Sometimes it’s quick, and sometimes it’s more stretched out. It can be a general expression of angst, a build up to an inflection point in the song, or just an extra sound effect. Like many of these other strange sounds, “buh” or “ugh” sees the vocalist using their voice almost as an instrument, rather than a means of saying anything concrete. Find it in songs like “Silence Speaks” by While She Sleeps ft. Oli Sykes, and in Immolation songs “Towards Earth” and “Apostle.”