September 26, 2018

Hunt Audio: Readability, Realism, and Consistency


A large part of Hunt's atmosphere is created via sound—the whisper of the wind, the ragged cawing of crows as a flock scatters into the sky, the distant howl of a bloodthirsty beast, the staccato blast of a rifle shot. The Hunt Audio Department is responsible for all of these elements and more. Creating realistic sound effects, building the aural atmosphere, adding new features, and bugfixing existing elements. As we work on all of these things, we always keep three elements in mind: readability, realism, and consistency.

Occlusion and Realism

Occlusion is the effect of one object in a 3D space blocking another 3D object in that space, which means, in the case of audio, that sounds coming from behind a wall should sound dampened or muffled, to take one example.

Technically, all sounds (emitters) shoot a ray to the player (listener) which checks whether there is an obstacle and what its surface type is. The denser the surface type, the more muffled the sound gets, so for example wood has a weaker effect than concrete.

While this works well for huts and buildings, it sometimes fails in underground areas. Throughout the last patches, we marked these areas with a special material in order to always get a high occlusion value. While this gave us the desired audio behavior, it has also meant that there are still a couple of edge cases where its not working properly.

Realistic sound propagation is a very complex matter, and we continue to refine and improve ours with every update.

Attenuation and Consistency

If it's going to sound realistic, game audio should become quieter over a distance and loose some of its high frequencies–just like it does in the real world. The challenge we face in games is the reduced field of view compared to the real world with its 114 degrees stereoscopic and 180 degrees of peripheral vision. The wider the field of view, the further away things look, even though their physical distance has not changed. This obviously affects our mix, as game audio has to match visual expectations. To counteract this, we came up with metrics and attenuation templates that we apply to the sounds based on their power. So a loud sound should be audible over a longer distance than a quiet sound, for example.

Especially on game-relevant elements such as the AI Cast and enemy weapons, we continue to do mixing passes to make it easier for the player to understand how far away–and thus how dangerous–something is.

Feedback and Readability

If you listen carefully, the world will speak to you, and players should be able to learn a lot about their surroundings in Hunt just by listening. Especially with the AI Cast, we want the player to be able to answer the following questions by ear alone: What is it? Where is it? Which state is it in? Answering these three questions allows the player to judge how relevant and therefore how dangerous something is.

Because of this, we put a lot of time into the AI audio design, and every AI cast member has a unique voice set. In addition, the intensity of their voice rises from ambient to aware to combat. Whenever an AI reaches a new level of escalation, it will emit a distinct, one-time sound to warn the player.

We apply the same questions and rules to the ravens, ducks, chickens, and dogs, as well as the interactive elements such as doors and generators, sound traps like glass piles and hanging cans, and of course the whole arsenal of weapons and equipment.

The goal remains to have a living and breathing world you can read by audio, and these three pillars are the foundation to our process in making that goal a reality. In my next blog, I will be back to talk in detail about making the audio for Hunt's ducks, which are a really good example of how we try to cater to realism, readability, and consistency—and the challenges that come up when we do so.

For all interested in a more in-depth explanation of the sound design in Hunt, Florian will be at EGX Berlin talking about 'Monstrous Sounds - The Audio in Hunt: Showdown', which you can stream on October 28th right here.

Play Hunt now on Steam.