God of War: Ragnarok dev reveals how he used his baby's real in-womb heartbeat to create the game's soundscape

God of War Ragnarok
(Image credit: Sony Santa Monica)

A God of War: Ragnarok developer has revealed that one of the game's subtlest sound effects is the sound of their baby's heartbeat from inside the womb.

In a recent tweet, PlayStation senior sound designer Alex Previty revealed what went into creating the sound effects heard during the Spark of the World section of God of War: Ragnarok. In a clip, you can see Kratos looking around the environment as a peculiar echoing sound rings out around him. Underneath that, a heartbeat sound rings out, adding a strangely visceral effect.

That's likely deliberate given the story implications of this part of the game, which I won't spoil here, but it turns out that that heartbeat effect is very real. Previty revealed that the sound "is actually my daughter's heartbeat while she was still in the womb," and that he recorded it using a Doppler - a fetal heartbeat monitoring device.

The rest of the noise comes from a children's choir, who Previty recorded as they were warming up. Both sound effects are dramatically slowed down - in a follow-up tweet, Previty demonstrated the original sounds, outlining the work down to create the eventual effect.

Previty's tweet is a fascinating peek behind the curtain of two different aspects of game development. On the one hand, there's the astounding, existential foley work that they document, showing how sound design can take an original sample and tweak it to capture an entirely unique mood. There's also a sense of how PlayStation's central teams help its first-party studios create their games - Previty doesn't work for God of War developer Sony Santa Monica, but for Sony's Creative Arts team, meaning that he's contributed to multiple games, including Marvel's Spider-Man 2 and the Demon's Souls Remake, in these smaller, more subtle ways.

God of War: Ragnarok just dropped its Valhalla update, featuring a roguelike mode so tricky that no-one on the dev team was able to complete its hardest difficulty

Ali Jones
News Editor

I'm GamesRadar's news editor, working with the team to deliver breaking news from across the industry. I started my journalistic career while getting my degree in English Literature at the University of Warwick, where I also worked as Games Editor on the student newspaper, The Boar. Since then, I've run the news sections at PCGamesN and Kotaku UK, and also regularly contributed to PC Gamer. As you might be able to tell, PC is my platform of choice, so you can regularly find me playing League of Legends or Steam's latest indie hit.