Martin Stig Andersen, the sound designer and composer for Playdead’s Inside wanted a different yet familiar soundscape for the indie platformer. His solution was to play it through an actual human skull.

"I had the basic idea of trying to recreate sounds as they would sound if they were happening inside your head," Andersen wrote in a post on Gamasutra. "That was the curious thought that led me to acquire a human skull and experiment with it."

Inside tells the cryptic story of a young person on the run from a mysterious evil, and plays with themes of mind control and genetic engineering. Our review called it a "jaw-dropping ... superbly crafted, beautiful game." It’s the spiritual successor of the critically-acclaimed Limbo, which was released in 2010.

"I didn't really want to hear synth music in the game," Andersen wrote. "I tried to do it, but it felt too much like a statement — like we wanted express something by subscribing to a specific genre. I don't think that's appropriate for a game like Inside, a small game that's all about creating its own unique world. ... But when I played them through a skull, the sounds acquired another quality.

"During the development we acquired an intuition for what kind of soundscapes resonated well within the skull. ... The end result, after the post-processing, is generally a bit creepy and cold. The sound has almost a chill about it. Eventually all the teeth fell out of the skull because of the vibrations, but while they were still there they created this small vibrating sound that I think was unsettling but also strangely familiar to people. Because we all know it, in a way."

You can listen to the difference in several samples available on SoundCloud and embedded in the original article.

We’ve reached out to Andersen to find out more about where and how he acquired the skull.