How do front speakers emulate surround sound?



I have a 2 speaker + 1 subwoofer setup for my computer and it’s really good. I can hear enemies coming at almost any direction, even behind me when I’m playing games. How do my two speakers in front of me make sounds that sound like they’re coming from behind me? Is it some sort of auditory illusion?

In: Technology

I’m not going to act like I know a ton on the topic, but it is something I decided to read up on a couple weeks ago, so I’ll give it a shot: we have two ears, yet we *already* somehow can tell sound direction. How? The way the sound has to bend around our ear and travel in differently gives it **tiny** timing delays, and we’ve learned to interpret those delays as direction. Companies have begun to research and try to replicate those delays, making the sound just a fraction of a second earlier or later and emulating direction. The general field is “binaural audio” or “binaural recording”

There is something called binaural audio (HRTF filtering) that creates auditory illusions by recreating the effect that the shape of your ears have on audio behind you etc to mimic uncanny localized sounds (there is a really good barbershop sound demo out there somewhere). But afaik that only works well with headsets.

TLDR; no idea

It has to do with the shape of your ear. Your eardrum is just like a microphone, it doesn’t actually know where any sound is coming from, your brain is just really good at picking up subtle clues in the sound that lets you distinguish the direction through the asymmetry of your ear. Well, what if you made it “sound” like when your ear hears it from behind, and then just played it through a speaker? Your brain would interpret the very subtle differences as the sound coming from behind you, even though it wasn’t. So yes, it is an auditory illusion created by making it sound like it’s behind you through subtle digital manipulation.