An enemy is firing in the distance and on the move, but they’re out of sight. As an elite Operator, every second counts. Are they down the hall, racing up the stairs, outside? The audio team at Treyarch is enhancing the 3D soundscape to new levels, allowing players to better sense the location, speed, and direction of nearby activity, helping them to respond more effectively and become even more immersed in the world of Call of Duty®: Black Ops 6.

To get a better idea of the audio enhancements going into the game, we spoke with Lead Audio Designer Collin Ayers and Expert Audio Engineer William Cornell. William (9 years at Treyarch) and Collin (18 years at Treyarch) are both long time Treyarch audio wizards, earning credits on multiple Call of Duty titles and acquiring valuable experience resulting in the team’s best work.

The Adaptive Battlefield: Listen and Locate

As with every Treyarch title, the audio team has redesigned or captured new sound effects for every single weapon in the game, including new reload and firing sounds. How those sounds interact with the environment, however, is being pushed to new limits using the studio’s most advanced audio systems yet.

“The goal for the audio team on Black Ops 6,” Collin said, “is what we’re calling the adaptive battlefield, a more purposeful and directional soundscape that focuses on the information players need when they need it while reducing the clutter of extraneous noise.”

Specifically, the team has been laser focused on distant firing sounds, giving players information on directionality, distance, and threat level so they can more easily identify where the enemy Operator is firing from and then formulate their plan of counterattack. “We want to make sure that the soundscape in this game will adapt to each player as they play, creating a living and breathing play space.”

Project Acoustics: Taking Spatial Reverb to the Next Level

As an Expert Audio Engineer, it is William’s job to make sure that all the sound design choices that Collin makes are presented to players in the best possible way. “Gunshots and grenades will realistically fill the space around them,” he said. “Footsteps will echo down long hallways, and the sound of rain and crickets chirping will come in through open windows and holes in the wall.”

In collaboration with Microsoft’s Project Acoustics system, advancements in spatial awareness and perception are being pushed to new heights. “We’ve been working closely with the Project Acoustics team to simulate the way that sound waves bounce and propagate through the world down to the smallest details like what materials are made of, the size and shape of the room, and what path the sound has to take to get from where it happened to where you’re hearing it.”

But don’t just take his word for it. Throw on some headphones and listen to the two following examples to hear the audio improvements firsthand, noticing how the environment clearly affects the sounds moving through it:

Example #1: Vocal Lines

Example #2: Enemy Footsteps

Sound absorption and reflection plays a role, too. Snow, for example, absorbs most of the soundwaves that interact with it while trees in a forest cause sound to reflect and bounce around. “It’s a bunch of tiny little pieces that all have to come together to replicate this natural listening experience that you get in the real world for free,” said William.

The Physics of Sound, Visualized

Project Acoustics models the complex wave physics of sound in a 3D game environment. This physically based acoustics approach ensures that game sound is heard like it is naturally meant to be without requiring traditionally used manual tricks.

In this example from Terminus, sound spatially reverberates and diffracts to flow between a large lab space and cave system on lower left, responding to the detailed geometry and materials in the environment. A player standing nearby will hear directional echoes coming from the cave’s mouth rather than all around them, resulting in a spatial reverb experience that enables them to anticipate by sound as in real life.

Live Mixing: Prioritizing the Most Important Sounds

In the heat of combat, some sounds are more urgent than others, and Black Ops 6 takes that into account by emphasizing the most important sounds to the player at any given moment.

“Our new priority system assigns a dynamic priority number to every single sound which can then be adjusted live in the entire mix,” said Collin. The sound of enemies moving toward you, for example, is emphasized more than the sound of teammates at your back. A zombie jumping off a building behind your Operator is prioritized over other sounds due to its imminent threat.

“All these systems,” he said, “including the priority system and Project Acoustics, are creating a game that will adapt to each and every player as they’re playing.”

Enhanced Headphone Mode: Greater Immersion through HRTF

The advancements in sound go even further as the game uses Head Related Transfer Function (HRTF) technology to better simulate how sound is transferred from the game world to the player’s ears. William explained that “HRTF emulates the way that sounds are affected by the shape of your head and your ears before you actually hear them. It’s the gold standard for maximizing directional perception when you’re listening on headphones.”

Enhanced Headphone Mode makes use of Embody’s Immerse Spatial Audio technology to increase the directional accuracy of sounds played in the world. Immerse Spatial Audio is compatible with any headphone or earbud model and greatly improves the player’s spatial audio experience. Included as part of the game’s Enhanced Headphone Mode, is a Universal HRTF profile which has been specifically created for the Call of Duty soundscape. Optionally, players can choose to enhance this HRTF experience even further by creating a Personalized profile that takes into account the player’s physical attributes, such as the shape of their ear or head. This customization is accessed in game and completed by using Embody’s personalization portal.

The Enhanced Headphone Mode will be available at launch for Black Ops 6 and at the start of Season 1 for Call of Duty: Warzone™.

Accessibility Support

Many people in the world suffer from hearing impairments. Interaural Asymmetry or Asymmetrical Hearing Loss occurs when the degree of hearing loss is different in each ear, making it difficult to localize sound sources in 3D space. Tinnitus - a ringing of one or both ears - is a condition where sound is heard without any source, making it uncomfortable to hear external sounds at certain frequencies in the affected ear. These conditions are also the two top concerns amongst military veterans.

Black Ops 6 features important audio accessibility options, including:

Asymmetrical Hearing Compensation: Adjust the intensity of selected frequencies in each ear to balance the sound field in a way that makes it appear symmetrical to the listener, improving the accuracy of in-game audio cues. It can also be used to reduce the loudness of frequencies that are uncomfortable to hear. At game launch, Asymmetrical Hearing Compensation will be available in Black Ops 6 Multiplayer and Zombies.

Reduce Tinnitus Sound: Replace the Tinnitus sound from Concussion and Flash Grenade shellshock with a dimmer audio cue.

We cannot wait for players to hear the audio innovations at launch on October 25, including other features like various audio mix presets, different hit marker sound effects, voice chat settings, and more.

Get the Latest on Black Ops 6

Stay one step ahead with the latest official Black Ops 6 information by checking the Call of Duty Blog frequently as we approach the October 25 launch date.

Call of Duty: Black Ops 6 is published by Activision. Development for the game is led by Treyarch, in partnership with Raven Software. Additional development support provided (in alphabetical order) by Activision Central Design, Activision Central Technology, Activision QA, Activision Shanghai, Beenox, Demonware, High Moon Studios, Infinity Ward, and Sledgehammer Games. 

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