It only takes a matter of seconds while playing a game to understand the importance of its sound. In addition to more straightforward uses of sound, like voice over or gunshot noises, video games use sound design to convey context, reinforce feeling, and heighten spacial awareness. Audio can either add to or subtract from the realism, surrealism, or hyper realism that a game is trying to present.
So in an effort to further my knowledge on the subject, and to hopefully pique your collective interests, today I’d like to take a closer look at one of the most commonly used tools in sound design: the Equalizer.
For the unaware, an equalizer is a software or hardware filter that adjusts the volume of specific sound frequencies. Equalizers work in different ranges of sound, otherwise known as bands. Simpler EQ’s may only have two bands, which are usually referred to as Bass and Treble; however, more expensive equalizers may possess upwards of 30 bands, or in other words, 30 different frequency ranges that can be manipulated. Knowing how to adjust these bands can completely change how a listener hears a certain piece of sound or music.
In sound design, one of the best applications of eq filtering is called cutoff filtering, or more specifically, high and low-pass filters. A low pass filter allows any frequence lower than its threshold setting to pass through uninterrupted while higher frequencies are reduced or completely removed. High-pass filters function in an opposite manner, allowing higher frequencies on the audio spectrum to bypass the filter while the lower ones are cutoff.
For example: Celeste, one of my favorite platformers, utilizes a low pass filter in a very macro way. Whenever Madeline, the player controlled character, finds herself underwater, a low pass filter mutes the higher frequencies of every sound or piece of music currently being played by the game. This imitates the same effect that water has on the human ear when it’s submerged. We could strip away all of the visuals and the player would likely understand that they’re underwater based on the game’s sound design alone.
Something else that I learned while researching EQ filters is the fact that aggressive low-pass filters can be used to give the impression of listening to a noise through a wall or large object. When driving a vehicle in PlayerUnknown’s Battlegrounds, the sound of the Dacia’s engine changes when the player switches between the third person camera and the first person camera. While this effect can be achieved by simply triggering additional layers of sound based on the camera that’s in use, we can achieve similar results by using a low pass EQ filter, just like the one that’s used in Celeste. When using the third person camera, the low pass filter is bypassed and thus the sound of the car’s engine is coming through to the listener completely unhindered. However, if the EQ filter is activated while in the first person perspective, the higher frequencies of the car’s engine are reduced, which produces a much more intimate sound. This type of sound makes sense because the camera is inside of the car, wherein there are multiple layers of plastic, metal, and glass between it and the car’s engine.
Rainbow Six Siege uses low-pass EQ filters, too. If an enemy operator walks on the ceiling above you, they’re footsteps are muffled and distant. If they’re moving within the same space as your character, their footsteps will be much more present and clear, which means the EQ filter is bypassed. The game’s sound design also activates a high-pass EQ filter anytime the player is in control of a camera or drone, which results in an audio effect that mimics a radio or a speakerphone.
I could further list out examples of games that utilize EQ filters, but I think you get the point: if in the proper hands, this basic & quite common audio tool can be used to create powerful and realistic sound effects that both elevate the quality of a game and serve to immerse its players. Take a few minutes during your next gaming session to play a game with its audio muted and what you’ll likely find is that the experience feels empty, foreign, or disjointed. Afterwards, crank the volume of your headphones and enjoy all of the gorgeous sounds spilling into your ears and know that someone out there spent a tremendous amount of time EQing them for you.