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September 2014
Issue: March 1. 2014

Audio For Games

By: Jennifer Walden
Building an interesting combat soundtrack is tricky because typically the gameplay is repetitious. There’s a lot of bang-bang-bang happening (or clang-clang-clang, depending on the era of the storyline). So how do you break the monotony? Offering players a variety of weapons is a good start, but that’s only scratching the surface. No matter the size of the arsenal, sounds need to change. Adjusting the EQ to account for perspective or adding reverb in spacious environments are effective changes that add variety and keep a game from sounding too gamey. Improving the game’s dynamic range also keeps the soundtrack from becoming stagnant, and it helps players from becoming sonically fatigued. These game audio pros share their combat game experiences, and how they build compelling combat soundtracks.

TITANFALL

Respawn Entertainment’s highly-anticipated debut game, Titanfall, is an online-only, multiplayer FPS game for Microsoft’s Xbox One, Xbox 360, and the PC. Erik Kraber is the audio director at Respawn Entertainment (www.respawn.com) in Van Nuys, CA. His audio team includes senior sound designer Tyler Parsons, sound designer Bradley Snyder, and dialogue supervisor Joshua Nelson. Kraber also worked with Warner Bros. Game Audio (http://www.warnerbros.com) supervising sound editor Bryan Watkins and his audio team in Burbank, CA.



Titanfall is a player vs. player game; six IMC (Interstellar Manufacturing Corporation) players battle against six militia players. Players are called Pilots when not in a Titan mech-suit. Each Pilot can summon a Titan. There can be up to 40 AI combatants in each game as well. In addition to combat weapons, there are tactical abilities and special Titan abilities happening. Each ability has a unique audio cue. Players hear messages through their helmet headsets. There’s a musical score running throughout to highlight gameplay, and to signal the end of a campaign. Needless to say, the soundtrack is incredibly dense. 

“At one point, we had 460 simultaneous voices of sound happening,” Kraber says. “Trying to control the chaos is a big focus and probably the biggest hurdle we had to overcome throughout all of it.”

A priority value is assigned to each sound. A sound that’s given a higher priority will attenuate all other sounds in the mix. For example, when a player gets a message through the headset, that sound takes precedence in the mix.

During the chaos of battle, Kraber and his audio team want to communicate as much tactical information through sound as possible. Senior sound designer Parsons says, “Players should know where the enemy is, what the enemy is firing, who was damaged, who was not, whose abilities are running out, and so forth. Finding space for all that information and providing it to the player became our biggest challenge.”

Titanfall’s weapon sounds reinforce the realistic-yet-futuristic look that lead artist Joel Emslie did for the game. Many weapons are ballistic-based with tech enhancements, though a few are energy-based. They sound relatable, almost familiar, yet with a sci-fi twist. “We all agreed that we didn’t want any ‘pew pew’ laser sounds,” says Kraber. “The ‘pew pew’ sound was a big no-no. If any sounds could be described in that manner then they were wrong for the game.” 

At Warner Bros. Game Audio, Watkins brings valuable weapons design experience to Titanfall. He worked with Kraber last year on the weapons for Medal of Honor: Warfighter, and he recently completed weapons work for Saints Row IV. Having experience with both ends of the spectrum, his weapon sounds for Titanfall tread the fine line between believably futuristic and too sci-fi. One weapon Watkins sound designed was the charge rifle, an energy-based sniper rifle used for taking down Titans. The rifle, he explains, has tendrils that move up and down during its idle. “To try and sell the little movements of the tendrils was fun,” Watkins says. In contrast, Watkins also created sounds for the much larger Titan weapons, such as the XO-16 chaingun. “One of our challenges was to make the Pilot weapons really big and exciting, yet still make the Titan’s weapons even more exciting and bigger still,” Watkins notes.



While discussing the direction for the Pilot’s Archer Rocket, a shoulder-firing, anti-Titan weapon, Kraber referenced the rocket launcher sound from the 2005 film War of the Worlds. Watkins contacted Richard King (supervising sound editor on War of the Worlds) to find out how he made it. 

“Richard King was very nice and got his assistant to pull the sounds for me,” says Watkins. “I took a listen to their pre-dub, and made my own version of it. Of course I didn’t tell Erik until I sent it. It was a very clever sound in how it gave you the sense of the rocket going out of the tube.” Watkins likens it to the sound of a cannon being cleaned out with a big swab. “It was exactly what Erik was trying to achieve on this game, which was to give every weapon a unique sound.”       

Highlighting each weapon’s unique personality through sound does two things: it instantly communicates an enemy’s location and threat level, and it keeps the soundtrack from becoming a constant wash of indistinct gunfire. Even when fired from varied distances, each weapon retains a core part of its personality. 

“If someone is 500 yards away firing the Arc Cannon, you know exactly what weapon it is,” Kraber notes, “even though it sounds different than it does when fired right next to you.” Kraber created the Arc Cannon sound using flanged, processed flame sources, like flame whooshes and burns, in combination with synth generated white noise. The Arc Cannon has a drastic range, notes Kraber, from a low-powered shot to a high-powered shot. 

“I had to figure out how to mix, balance and create this design so you could tell it was the same weapon but it really felt amped up at times,” he notes. He also created the ‘Kraber Sniper’ rifle sound, which features a distinct crack followed by a three second echoing decay. “If you hear that crack and that long decay,” says Kraber, “then you know that sniper’s bullet can reach you.” 

Another interesting weapon is a gigantic orbital railgun that defends one of the frontier outposts. Parsons, who created the railgun sound design, notes the gun has an enormous warm-up and cool-down cycle that involves many moving parts. To create the sound of the moving parts, Parsons used recordings he captured of a malfunctioning escalator in Thailand that has “huge sounding clunks and servos,” he says. The sound also includes a box crusher that Parsons recorded at a grocery store. For the railgun discharge, Parsons recorded the revving of a Yamaha motorcycle, which he then processed using the Shift plug-in from the GRM Tools Spectral Transform bundle, the iZotope Spectron plug-in, and tons of EQ and compression. Parsons confesses, “It was definitely the biggest weapon that I have ever done.”



There are three classes of Titan chassis: the commonly used Atlas, the heavy Ogre, and the agile Stryder. Snyder, who was the first sound designer at Respawn, created the sound for the Atlas Titan. His Atlas sound design established how all the Titans should sound. Snyder’s approach stemmed from the idea that the frontier people were like farmers. “What if this was farm technology that they had militarized?” he asks. Snyder combined familiar machine sounds, like pallet jacks, with energy-based elements to give the Atlas a working machine sound with a sci-fi edge.

The Ogre Titan chassis is the most heavily armored. It sounds heavy and lumbering compared to the others. Parsons’s sound design has a guttural, bestial quality to it, with growly-sounding servos when it moves. “When the Ogre is just walking around, the chassis has a very tight sound, but when the Ogre runs, its dash sound has a snarling roar. It’s meant to sound as intimidating as possible,” says Parsons.

The Stryder is the smallest, fastest Titan. Kraber, who created the Stryder sound, felt it was very cricket-like. It’s able to dash around the environment very quickly. It has a more nimble, less lumbering dash sound compared to the other Titans. “It has this ‘wheeeee’ sound to it,” explains Kraber. “Sort of a descending pitch. It sounds cricket-like with whistles and pitch shifting hydraulic elements.”

To balance gameplay between Pilots and Titans, Pilots have special tactical abilities, like Cloak and Stim, to help them counter Titan attacks. Abilities only last for a finite amount of time. Each ability has a unique audio cue. As the ability runs out, the sound’s pitch rises. The sound for the cloaking ability, which makes a Pilot  invisible, can be heard by other players within 40 feet. 

“The cloaking sound works against the ability and that helps keep the ability in check,” says Kraber. The Stim ability makes Pilots move and heal faster. Snyder’s inspiration for the Stim sound came from the stimpacks given to Marines in StarCraft. Since Stim is like a hyper-drug, Snyder worked medical sounds into the design, like the jolt of a defibrillator, and an elevated heartbeat. “It almost gives you this feeling that you yourself are on the drug and you’re running around faster in the world,” Snyder says. 

Titans also have special abilities, such as Electric Smoke and Shield Wall. The Electric Smoke sound has two distinct parts: the initial deploy of a canister popping open, and a cloud of smoke with rippling electrical sounds. Snyder, who designed the sound, says, “It’s as if the Titan has a smoke grenade. Not only does it mask the Titan’s position, the electricity damages whoever is in the smoke.” Snyder’s design for the Shield Wall is a combination of heavy castle gate sounds that give the deploy an almost physical feel, followed by a synth-based energy sound.

“In addition to the portcullis sound, the Shield Wall has many layers of synth elements that were manipulated using the GRM Tools Spectral Transform bundle,” says Snyder. Overall, the sounds of the ballistic-based gunfire, explosions and Foley for both the Pilots and Titans, are more prevalent than the synthy sound design elements.

Titanfall uses separate scores for IMC players and militia players. The IMC is a technologically-advanced corporation, so large it seems unstoppable, explains Kraber. Composer Stephen Barton made the IMC score more electronic, with soft, fuzzy distortion and big orchestral arrangements. In contrast, Barton’s militia score uses small orchestral instruments, and a wide variety of ethnic instruments from all different regions and cultures, making it feel more organic. “When you play either side, it feels like a different story. The score and the sound design unite the players to their side. Stephen did a great job with the soundtrack and defining the initial sound of the IMC and the militia,” says Kraber.   

To make up for a lack of in-game DSP, such as reverbs and EQ, the Respawn audio team relied on creative sound design techniques. They authorized assets for multiple distances with multiple layers, to achieve a sense of varying distance and changes in environment. 

“Between the sound design collaboration of our team and Bryan’s team at Warner Bros. Game Audio, and the audio implementation work here at Respawn, we were able to achieve DSP-like effects in-game with many dynamic samples and many layers of sounds,” says Kraber says.

Watkins gives the example of a proximity mine he delivered to Respawn. Between the distance variations of close, medium, and far, he sent 112 LCR tracks to Kraber, with the center channel being the point source material. 

“Our focus here is to deliver a lot of layers so Erik and his audio team would have the ability to mix our elements so they make sense in-game,” says Watkins. All the little subtleties help to prevent monotony, and keep the sound from being too gamey, adds Kraber. Since the game is online-only, Respawn can continue refining the soundtrack. “The last thing you want is to have the players be confused or fatigued. It’s very easy to get that way, especially with a massive game like Titanfall. We did our best and at the end of the day we know now what we are going to be improving on later.” 

SAINTS ROW IV

On Saints Row IV, Bryan Watkins is the sound design supervisor at Warner Bros. Game Audio (http://www.warnerbros.com/)in Burbank, CA. He worked with project audio director Brandon Bray at Deep Silver Volition, LLC (http://www.dsvolition.com) in Champaign, IL. Saints Row IV is a third-person shooter game with an open-world environment that gives players the choice to complete campaign quests in the main storyline, do secondary missions, or just wreak havoc and destroy everything they see. 



Initially, gameplay feels similar to recent Grand Theft Auto games, but Saints Row IV takes everything to the extreme. From storyline, to weapon choices and superpowers, to character dialog, there is only one word to describe Saints Row IV: crazy! Bray says, “Our two mantras for Saints Row are: ‘embrace the crazy,’ and ‘fun trumps all.’ If it’s not fun, we’re not going to put it in the game.” Saints Row IV is nominated for a Game Developers Choice Award for Best Audio.  

Saints Row IV introduces superpowers, aliens and other sci-fi elements that were never part of the franchise. There’s an incredible sandbox of toys available to players that reinforce the feeling of power, and what Bray terms as “badassery.” An example of available superhuman abilities include: Blast, the ability to freeze people and smash them into a million frozen pieces; Telekinesis, the ability to pick up and throw cars and people; and Stomp, a foot stomp that creates an acute earthquake. Stomp was one of the first sounds Bray created for the game. 

“When you lift your leg up, it’s this reverby, high-pitched zip sound,” says Bray. “And that’s all it is, a bunch of processed zippers to give you this ascension before you stomp your foot down and cause hell.”  

Saints Row IV offers a variety of new, and creative weapons such as: the Inflato-Ray, the Black Hole Gun, the Abducto-Matic, the Disintegrator Rifle, and the Dubstep Gun. The business end of the Dubstep Gun looks like a speaker. When fired, it makes all pedestrians and vehicles in the area dance in time to the music. Bringing the gun from concept to reality required the audio, art, weapons design, and programming to all work in sync. 

The main obstacle for audio, notes Bray, was how to trigger the visual effects in tempo with the music. “It was actually a relatively simple answer because we had done something similar on Saints Row: The Third,” says Bray. They embedded markers as metadata into the wave file. Those markers have different names, such as rifle and cannon. The smaller rifle visual effects fire out of the tweeter and the cannon has larger effects that come out of the woofer. Depending on the marker name, it would do different things via the code.

“You pull the trigger and it would start playing music. The music is what triggers everything else in the world to happen,” Bray explains. In addition to the visual effects, the markers also trigger other things, like the surrounding lights to flicker, the cars to bounce up and down, and the pedestrians to pop and lock as they dance. “It turns into this giant rave party and what better type of music to kill people with than dub step,” he jokes.

The Disintegrator Rifle makes people disintegrate into 1s and 0s. To create the sound, Bray used processed bird screeches, metal scrapes, synth elements, and tons of processing. “It was a lot of synth tones that I ran through plug-ins from GRM Tools, as well as Serato Pitch n’ Time Pro,” says Bray. “I used modulators, phasers and frequency shifters. I was going for that Lawnmower Man, digitizing, bit-crushing kind of sound.” Bray describes the sound as “a sci-fi falcon getting punched in the face.”



According to Bray, Watkins and his audio team at Warner Bros. Game Audio did the majority of the weapon sounds. One new feature of Saints Row IV is the ability to customize weapons. Changing the look of the weapon changes the sound. For example, you can make the rocket launcher look like a guitar case. “One of my sound designers here, Mitch Osias, used an out of tune guitar strum along with the shot, so when you fire the RPG you get this nice twang,” Watkins notes.

Since there are aliens in Saints Row IV, Watkins and his team created sounds for the alien arsenal as well. “The alien weapons that Bryan and the Warner Bros. team did were absolutely fantastic,” says Bray. “We had these ‘murder-bots,’ which were our Terminator-esk aliens. They had mini guns and mine launchers, and those sounds were so awesome.” 

Watkins’ approach to weapons typically starts with metallic or sci-fi sounds to which he adds real sounding weapons for size and power. He used S-Layer by Twisted Tools to blend and manipulate sounds to create interesting sci-fi palettes. S-Layer is built for Native Instruments’ Reaktor 5. 

“We would take the sounds we made with S-Layer and start adding them to the weapon we were trying to build,” says Watkins. “That’s how we did a lot of the sci-fi-type weapons. S-Layer was sort of the magic tool for this game.” 

“We also built our UI and interface audio using S-Layer,” adds Bray. “That program was used throughout the game for certain. It’s a fantastic software.”
The giant Warden alien vocalizations were performed by actors who specialize in creature voices. Watkins also performed various screams for the Warden aliens. He pitched down his vocals using Serato’s Pitch ‘n Time Pro and layered it with sounds of gorillas, buffalo, pigs, lightning bolts, and metal clashes to make a big booming roar for the Warden. Watkins says, “The alien Wardens were fun because they were more animalistic. They didn’t speak English; they just made noises. They had to sound scary but not cartoony. We wanted people to be frightened by them.”   
 


Warner Bros. Game Audio hired Joshua Nelson to handle implementation of their audio assets. Warner Bros. was connected to Volition’s server in Champaign, IL, via Perforce, a development platform for implementing and managing source code and digital assets from off-site and on-site collaborators. Watkins delivered the weapon sounds to Nelson, who made adjustments based on how they sounded in-game. Once Watkins gave approval of the sounds, they were checked into the game’s build at Volition for Bray’s final approval. 

Warner Bros. Game Audio also did the sound for in-game cinematics, and the non-interactive sequences that happen during gameplay. Nelson worked with audio designer Kyle VandeSlunt at Volition on a non-interactive sequence in the White House mission, where one character does a surfer slide down a broken podium then jumps into a giant turret gun. Bray notes those sounds were actually done in mono, and mixed into the game using 3D panning in Audiokinetic’s Wwise. Once everything was good to go, Nelson synced the sound to the latest build from Volition. 

“When you sync the build it takes a long time because it’s encrypted data,” explains Watkins. “We would try to do it over the weekend because it would take about 24 hours.” Despite the challenges of working off-site via Perforce, Watkins felt integrated with Volition’s audio team because they were part of Volition’s Outlook mail system. “We knew when they were taking the build offline, or when certain parts of the game were being checked out. We also sent them emails to say when we were checking out the weapons and adding sound. So, they were aware of what we were up to. It was a really neat way to work.”

Saints Row IV is an open-world sandbox. Besides mission progression, players aren’t given much direction. They can do whatever they want. Bray says, “If they want to take RPGs and blow things up for half an hour, they can do that. And we have to make sure that the sounds don’t get repetitive.” 

Building a compelling combat soundtrack requires the creative use of every audio aspect, and Saints Row IV is able to go sound-crazy. There are tons of creative weapons, and places to explore. There are changeable radio stations that play in the vehicles, and if the player chooses to super sprint or fly around town, music plays as if it’s coming from an MP3 player.



“The parameters we set up in Wwise have music transitions based on elevation, says Bray. “As the elevation drops, the songs crossfade. It sounds very natural because the score, composed by Malcome Kirby Jr., is very atmospheric.”

With so many opportunities to change the sound, it’s hard to image the track becoming repetitive. But, as Bray points out, a player can “stay in one corner for three hours and just fire the same weapon over and over.” Through Wwise, Bray can make slight changes to vary the pitch and volume during playback so the sounds don’t get monotonous. 

“If it was just three sounds over and over again, it would get really annoying, and the first rule of game sound design is thou shall not annoy,” says Bray. “We are the only discipline to allow you to shut us off. You can turn off the sound effects, you can turn off the voices, and you can turn off the music. You can turn off everything. So we do everything we can to make sure that doesn’t happen.” 

RYSE: SON OF ROME

Ryse: Son of Rome is a third-person action/adventure combat game following Marius Titus as he rises through the ranks of the Roman army. Players control Marius and lead Roman troops in battle against barbarians in Britannia. The story eventually takes Marius back to Rome. The game was developed by Crytek (http://www.crytek.com/) and published by Microsoft Studios (http://www.microsoft.com/games) exclusively for Xbox One. The game was released in November. Crytek’s audio department in Frankfurt am Main, Germany, led by audio director Simon Pressey, collaborated with the audio team at Microsoft Game Studios in Redmond, WA.  

The Ryse: Son of Rome player has a limited arsenal: a short sword called a Gladius, a large rectangular shield, and a javelin-like weapon called a Pilum. Combat is pretty basic; you block blows from your enemy’s weapon (typically an axe) and stab them with your sword. Creating a compelling combat soundtrack using a limited weapons palette was the biggest challenge Pressey and his audio team faced. 



So, how did they keep it from sounding repetitive? “That was difficult,” confesses Pressey. “We recorded many different impacts of sword-type objects hitting metal, brick, wood, you name it. We recorded metal clangs in scrapyards, and abandoned buildings. We looked for fairly quiet places outside where we could hit things and record them.” They also recorded impacts for swords hitting flesh. “There’s a whole variety of fruits that we turned into salad,” jokes Pressey. Combat sounds in-game are made up of three layers, and each layer is randomized, so players never hear the exact same sound twice. There is also randomized pitch and volume of the three sound layers. 

Combat sounds are based on the player’s perspective. Sound sources three feet away will sound different than a sound source 10 feet away. “It’s a different set of layers you’re hearing and that creates a depth of field to the hack and slash soundscape,” explain Pressey. For example, hacking off an enemy’s arm at two feet away will sound more gorey than an enemy’s arm being hacked off five feet away. Varying the focus and intensity keeps battles from becoming a wall of sound. It also helps focus the player on immediate threats. “It was a very tricky balance finding that point where you are immersed in battle, surrounded by fighting, but the focus is on the fighting you are doing. That was the thing that we pulled off quite well,” says Pressey. He adds that being selective about what the player hears is key to the success of the sound design.    

In Ryse: Son of Rome, barbarians hurl flaming boulders at the Roman soldiers. The sound of the boulder flying through the air is a combination of rocket whooshes mixed with the sound of charging elephants. The impact sound uses explosions that Crytek recorded for their Crysis franchise, sweetened with close-up details of debris.



“We spent a lot of time breaking things and recording them to get the close details of things like splintering wood,” says Pressey, noting that the dynamic range of the game’s mix is a critical factor in selling the magnitude of the boulder impact. “We have plenty of headroom to make the boulder explosions be very big, and as we like to call it, ‘the best boulder ever,’” he says.

The dialog in-game was recorded on-set at the motion capture studio. All of the dialog recorded on-set has facial capture. There are 245 bones in each character’s face. The high resolution facial motion capture in combination with the actors’ on-set performances, make the dialog and exertion sounds feel very realistic. 
“The fact that we are marrying the image and the sound all the time, for all of the in-game dialog, makes for a visually powerful thing,” says Pressey. “You feel the pain. That is the idea. You see it on their face, and you hear it, and you feel it.”

For vocalizations, there is a distinct difference between the Roman soldiers and the barbarians. Pressey notes they went even further by creating a language subset for the Celts. “When the Celts scream or shout, they have their own inflection that is unique to them,” he explains.  

Other elements include detailed Foley for the Roman soldiers (down to a pair of hobnailed sandals with thick leather soles and iron studs sticking out of them that were built as a replica of real Roman troop sandals) and a cinematic score that was a creative collaboration between Crytek’s composers Borislav Slavov and Peter Antovski and Dynamedion’s creative director and composer Tilman Sillescu. 



Pressey notes that Ryse: Son of Rome is mixed in 7.1. He feels the bigger sound field allows him to be more precise. A lot of time was spent defining how loud the sounds around the player should be. Pressey’s particular attention to the dynamic range of the mix is one reason why the sound is so compelling. 

“It’s very easy for sword fighting to fall into the clang-clang-clang-boom-clang-clang kind of thing. To get out of that canned sound, we use dynamic range so we’re not always loud all the time, every single time you clang swords. We have very dynamically-changing sound. You can hear the dialog nicely, but then you have moments of intense sound, followed by more easy-to-manage bits of sound.” 

Pressey recommends using a 7.1 system while playing Ryse: Son of Rome. “The more speakers the better,” he says. “It adds quite a new dimension to the game.”