How Headsets Trick Your Brain Into Hearing Surround Sound

Image: EPOS.

This article has been sponsored by EPOS.

Directional audio is pivotal to gaming, especially when it comes to competitive first-person shooters like Counter-Strike or Overwatch. Not being able to tell when an enemy is coming up behind you and from which precise location often ends with you losing a round.

When you’re watching a movie or gaming on a 7.1 surround sound speaker setup, it relies on factors like the acoustics of the room and the space between your ears and the drivers (the actual speakers pushing the sound) to carry the sound, all of which play an important role in how you hear and interpret it. Given the speakers in headsets are placed right next to your ears, they need to work differently to properly replicate the effects of realistic sound.

There are a few tricks headsets use to emulate the effects of 5.1 or even 7.1 across two different methods — using multiple drivers in each ear, or by using a single driver in each ear and manipulating how they work via software.

Some may refer to the former as “true” surround sound, as it uses multiple drivers to send sounds to your ears from different angles, while the latter relies on slightly trickier software and complex algorithms to fool your brain into processing sounds as coming from different directions around you.

In true 5.1 or 7.1 surround sound headsets, the principle works the same as it does for a room setup, with the first number indicating the number of speakers (5) and the second being the subwoofer (1). The difference, of course, is that it’s replicated in each ear.

True and virtual systems essentially achieve the same goal, and whatever the method, both rely on the principles of psychoacoustics, which is the way in which humans perceive different sounds. Playing sounds at different angles and volumes, very slightly offsetting the timing of them in different ears and utilising the complex architecture of the outer ear are just some of the tricks used to fool your brain into perceiving directional sound in headsets. Howtogeek.com explains this using a real-world analogy:

Imagine someone directly to your left is speaking to you. You’ll hear the sound of their voice in your left ear, of course, but you’ll also hear it in your right—just with a lower volume and an almost imperceptible delay. Turn your head to face the person who’s speaking, and both your ears should hear the words at approximately the same time and the same volume. Even normal stereo audio mixing for music and television takes account of this; a singer or instrument is almost never heard completely in one ear or the other.

A great (and slightly unsettling) example of these techniques can be heard in the virtual haircut clip below, even on a baseline set headset.

Companies like EPOS maintain their competitive edge by keeping a lot of their sneakier tricks and algorithms a secret, so there’s a lot we wouldn’t be able to delve into, but it goes to show just how deep the field of psychoacoustics can be.

When it comes to gaming, there are headsets that are purpose-built to deliver better performance, helping players pinpoint where key sounds are coming from. While the sound mix of each individual game also plays a part in this, headset manufacturers can do a lot to enhance the experience. EPOS, for example, uses its own surround sound algorithm specially designed for the real-life replication of gaming audio. 

“We have used our understanding of how human anatomy and the brain capture and perceive sound to create a sense of realistic immersion,” the company says. “If you are in an RPG and two characters are having a conversation to your right, with our surround sound technology the sound arrives at your right ear before it reaches your left ear – just as it does in the real world.” 

Advanced units like the EPOS | Sennheiser GSP 670 wireless gaming headset will offer greater advantages through customisation, including the ability to pair with the EPOS Gaming Suite software that allows you to change and create EQ profiles based on what you’re using them for. You can even create profiles for individual games or genres like FPS, horror, RPG etc. If battery life is a concern, the EPOS | Sennheiser GSP 370 wireless gaming headset offers a whopping 100 hours of battery life.