What makes the audio of Mario Kart 8 so fantastic?

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Illustration: Derek Abella

Fewer games have more presence in the video game zeitgeist than the Mario Kart series.

Since the first release in the series, Super Mario Kart in 1992, the games have effortlessly combined the mechanics of a battle game with a kart racer and have become a staple in the world of multiplayer party games.

With each release, the games themselves have grown in both depth and innovation, and with that, so has their audio. In classic Nintendo fashion, the games are filled with riveting music, catchy melodies, and iconic sound effects; you’d be hard pressed to find a person familiar with video games who’s unfamiliar with the sound of an item box shuffling.

The most recent mainline game in the series, Mario Kart 8, was released on the Wii U in 2014 and subsequently re-released as Mario Kart 8 Deluxe in 2017 on the Nintendo Switch. Mario Kart 8 is a masterclass in game audio and music. But how does the sound of a game that’s known mostly for its split-screen local multiplayer shine through so stunningly, in such a difficult gameplay context? Let’s explore.

1. Music

It’s impossible to play a Nintendo game, let alone break down the audio of one, without mentioning its music. The music of the different courses in Mario Kart 8 spans a myriad of genres, from the soaring orchestrations of Cloudtop Cruise to the high-octane riffs of Big Blue. The catchy melodic content of each course’s music rivals the best hooks found in today’s pop music, and the explosive arrangements give each song the quintessential Nintendo character—something that has become so common in their titles that we as players often take it for granted.

High-level implementation

The music in Mario Kart 8 not only shines in its melodic content and arrangement, but equally in its implementation. Throughout each of the games in the Mario Kart franchise, there’s an understood basic implementation formula where a musical loop related to the course’s thematic material persists for two laps, and then a series of changes occurs to the music in the final lap; the music will often increase in tempo and modulate upwards in key.

Though there are a core set of courses in Mario Kart 8 that don’t deviate from this tried-and-true formula, there’s a non-trivial amount of courses that have unique implementation patterns specific to the gameplay or environment. For instance, Mount Wario is a sprint from the top of the mountain to the finish line at the bottom, differentiating from the more common lap-based race formula in both game design as well as music. Each section of the race introduces a new section of music that grows in intensity as the player progresses through their descent to the bottom.

Aesthetic-driven implementation: Animal Crossing, Electrodome, and Music Park

Many implementation techniques within the courses of Mario Kart 8 are aesthetic-driven. Animal Crossing, for instance, is a course that changes its scenery based on a randomly selected season (autumn, winter, spring, and summer). The musical arrangement changes alongside the seasons to be more fitting to the mood provided by the course’s scenery. Though this does not have a direct impact on gameplay, this almost subliminal change in musical content makes all the gameplay pieces fit together that much more.

Electrodome and Music Park are two examples of courses where the player’s actions interact directly with the environment, which in turn, has a direct effect on the music. Music Park features multiple instruments as part of the physical road; when the player drives over a piano or xylophone, they can hear different keys being played in tune with the music, no matter what point in the song the music is at.

Electrodome similarly features arpeggiators as part of the road and as a series of platforms that the player must drive over. As their kart makes contact with each platform, a percussive hit is played in time with the music that rises in pitch to act as a build up to the player reaching the other side. In a single-player kart racing experience, these function as aesthetic components that bring the environment to life (and allow the player to interact with music in classic Nintendo fashion).

Gameplay and location-driven implementation: Baby Park, Cloudtop Cruise, and Wario’s Gold Mine

There are also maps with implementation changes that tie closely to gameplay. The Baby Park course is a frenetic seven-lap sprint on a basic map that resembles a miniature NASCAR track. The gameplay on this course is quite chaotic, and as such, the music changes between each of the seven laps. These changes can vary from arrangement changes to modulations to changes in thematic material, all building up to the frenetic final lap sequence.

Changes in laps happen so frequently on this map that the music not only serves aesthetic purposes, but also functions as a constant game state notifier for the player. Changes in laps on this map are often easy to overlook; the constant evolution of the music creates a comical thread that fits the course’s gameplay while building to the final lap.

Beyond courses with implementation techniques that embody the full map, there are also others with more subtle changes in music. Cloudtop Cruise is a map in the clouds with a sprawling orchestral musical palette that references the famous “Gusty Gardens Galaxy” theme from Super Mario Galaxy. However, when the player enters the course’s thundercloud portion, the arrangement changes to a pulsating, guitar-driven arrangement of the same thematic material. This persists for the duration that the player remains in the thundercloud.

Location-based vertical remixing (where the arrangement of the same thematic material changes based on game data) is something that occurs in unique ways across multiple courses in Mario Kart 8. Wario’s Gold Mine, for instance, ties this technique closely to sound. When the player passes through a tunnel filled with bats and Shy Guys, the player hears the unmistakable Shy Guy vocalization sound repeatedly in time with the music. This serves as both a novel way to tie a player’s location to gameplay as well as yet another way for Nintendo to incorporate iconic sound design elements from their franchise into their music.

2. Sound design

As we touched on at the beginning of the article, one of the things that anyone who has played a Mario Kart title can appreciate is its highly communicative sound design. Immediately recognizable sound effects punctuate the soundscape and inform the player of exactly what’s happening at any given moment. In Mario Kart 8, there are subtleties to the soundscape that add to the overall aesthetic of a race—the item box shuffling sound, for example, is relatively tuned to the course’s music. This allows a sound (that could be abrasive if out of key) to feel like a natural part of the soundscape, while still achieving its communicative function.

Notification-driven sound design: Red Shells and Green Shells

These item box sounds, and other similar notifiers that are often taken for granted, hold a greater responsibility in the larger scope of the game. When a player drives through an item box and it begins shuffling, there’s a very explicit action that’s taking place. The player is waiting for an item, and then they immediately have access to it when the sound ends. Likewise, when a player finishes a lap in a race, the consistent sound effect compliments the on-screen visual. A basic principle consistent through each race is that important actions have a unique sonic signature.

This extends to when the player is receiving a boost, drifting, being hit by an item, or most notably, endangered. When a Red Shell (which effectively acts as a guided missile to a single target) is approaching the player, repeated beeps are heard within the soundscape. This compliments and gives more awareness to the visual notifier that appears at the bottom of the screen, in order to inform the player of their impending danger.

Conversely, when the player is about to be hit by a Green Shell (which is less dangerous), they will hear the corresponding sound as the shell comes into view in their camera. However, when the shell is outside of their field of view (and therefore not a threat), it’s as if it doesn’t exist.

Multi-channel communicative sound design: Speed boosts, kart sound effects, and top speed

Many of the actions in Mario Kart 8 communicate through multiple aural and visual ‘channels,’ providing the player multiple means to interpret an in-game action. This technique is not only important to video game accessibility, but also demonstrates mastery from a design standpoint, greatly improving the cohesiveness of the experience.

For example, multiple channels are activated when the player receives a speed boost. When a boost occurs, a fire comes out of the kart’s exhaust with a corresponding sound, the engine revs, and the player’s character shouts a reinforcing vocalization. In a game with a high amount of on-screen chaos, these auditory notifiers effectively help convey an important game state to the player.

That said, communicative sound design can extend further than notification-driven sounds. Consider the player’s kart sounds. As mentioned, the player is notified when the kart receives a boost or is stalled out. What about when the player is accelerating? The ramp of the player’s vehicle engine sound changes based on how quickly a vehicle is accelerating. This may seem like a basic aspect of vehicle sound design, but consider the many types of vehicles in Mario Kart. There are tons of different karts and motorcycles, each with customizable components that can have an impact on the player’s strategy for driving.

Next, consider the different states that a player may find themselves in while accelerating. The player may have just slipped on a banana on the bottom of a hill, requiring them to slowly make an uphill ascent. On the contrary, the player may have slipped on a banana at the top of a hill; in this case, their downhill descent will be complemented by quicker acceleration, as implied by the corresponding engine ramp sound effect. Though subtle, these slight variations in engine sounds subliminally add tension and release to suspenseful moments in a race.

Additionally, ‘top speed’ is a key mechanic in Mario Kart. This idea is especially important to convey from a sonic standpoint, considering the game has no visual speedometer. Due to this, it’s entirely up to the sound designer to communicate when a player has reached their highest speed during a race. When a player hits their top speed, they hear the engine consistently resonate across similar frequencies for an extended period of time. Of course, haptic feedback and vehicle handling help convey to the player that they’ve reached their top speed as well, allowing for a sense of synergy between sound and gameplay.

This mechanic is even more important in Mario Kart 8 due to the fact that as the player collects coins, their top speed increases—and this is also indicated primarily through sound. On a larger scale, slight alterations in sound design are generally driven by the overall state of the game.

3. Sound states driven by game states

Within a single race in Mario Kart, a player will be confronted with many different types of game states that can alter the nature of the gameplay. We previously discussed the final lap and the changes in music that accompany it as an example of a primarily aesthetic state—below, we dive into some other categories and instances.

Generalized sound state shifts: Being in first place and getting hit by Lightening

There are many more situational game states (all complimented by audio) that the player might find themselves in. An example is when the player is in first place. Once the player has remained in this position for a meaningful amount of time, an additional musical layer—usually a pulsating percussive layer that falls on the music’s downbeat—is mixed in with the core soundtrack of the race. This subtle layer adds energy to the race and underscores the increase in adrenaline that the player might be experiencing from being the frontrunner.

Players who fall victim to the Lightening item are subject to a change in game state as well. When the player is affected by this item, their kart (as well as everyone else’s) shrinks and moves slower. This change in kart speed is reflected by a change in the pitch of the engine sound. The music also comically reflects this game state by significantly increasing the pitch of the music. These changes across the audio playfully reinforce the fact that the majority of the racers are now tiny.

Isolated sound state shifts: The prioritization of audio elements

Aside from these sweeping game states, more subtle aspects of a race are also underscored by changes in sound. When a player is driving through a tunnel, for instance, a reverb is applied to their kart sounds and vocalizations.

On the other hand, when the player is surrounded by other players and in the midst of chaos, their own engine sound will be ducked in favor of other sounds that are more pertinent to the current gameplay—these could include enemy items, vocalizations, or even kart engines. During these moments, the player’s attention is turned towards the chaos around them, and their own engine sounds become significantly less relevant.

The primary goal of the audio design in Mario Kart is to inform the player about what’s most important to them at any given moment. In a chaotic game state with pumping music, flying items, and revving engines, the things that the player would be most concerned about are the sonic elements that are occurring in their immediate surroundings. If the player is perfectly safe, it’s not important to underscore an enemy being hit by a shell half a lap away. However, if an enemy gets hit by a shell directly next to them, the player would most likely want awareness of both the shell impact and the engine sounds of the kart creeping up behind them.

4. Single-player and multiplayer contexts

The Nintendo Switch as a gaming platform also presents a unique challenge for the audio team in a single-player race. This is because the game’s soundscape needs to remain clear with the built-in speakers of the Nintendo Switch system. Though the onboard speakers of the Switch are configured to stereo, when listening to a game without headphones, it presents a very narrow stereo field. Therefore, the audio team needs to rely less on panning techniques to create the overall soundfield.

This can be difficult in a video game with gameplay as hectic as Mario Kart—how does one decipher a soundscape that includes several different go-kart engines surrounding the player, items flying everywhere, and multiple players skidding and wiping out without a wide stereo field? The answer lies in a prioritization hierarchy, which is important to a single-player experience, but becomes even more important when local multiplayer is involved.

Speaking of which—one of the most common ways to play Mario Kart is using local split-screen multiplayer with multiple players racing against each other in the same room, on the same television. This type of gameplay presents the same challenges as the single-player experience, in addition to even more variables.

Instead of having just one player’s kart, there are now up to four players sharing the same screen, occupying the same speaker soundscape. Additionally, each of these players have their own kart engine sounds as well as their individualized game states. This introduces a high magnitude of chaos to the soundscape; how do the audio designers of Mario Kart 8 tackle these challenges?

Working with multiple player engines and listeners

The first and most prominent challenge to deal with is the player kart engines. Unless there’s a surround system in place, there aren’t four speakers available to place each of these kart engines (and even if there were, that strategy would create a very disjointing audio experience).

Instead, player karts are panned to the side of the screen where their player is visually assigned during a split-screen session. This not only localizes the player engine sounds, but also frees up the ‘phantom center’ of the stereo mix for sounds that are the most important to the overall experience.

Since each of the individual players will have their own individual game state, it’s important to not only discern what’s important to the individual players, but also what’s important to the game as a whole. For example, player 4 slipping on a banana might be a more minor action in comparison to the fact that player 1 is about to be hit by a Red Shell. One of the most remarkable aspects of the soundscape in a local multiplayer session of Mario Kart 8 is that every player seems to always be aware of the most important sound or action that’s occurring in a race.

Sound states driven by the overall game state

Because there’s one piece of looped music per level, matching music to gameplay is a deceptively simple task. As previously stated, the music responds to various player states, including when a player enters their final lap and when they’re in first place—but with multiple players sharing the same screen, this poses an issue. As a result, the music implementation tracks the frontrunner relative to all other local players. For example, if player 2 is the first to enter a final lap, the final lap music will begin playing. Likewise, if player 3 moves into first place, the aforementioned musical layer will start to fade in over the music.

This implementation strategy has some proxy benefits as well. Music tracking the frontrunner also relays important information to the other players in the room. Is a player among us in first place? Has someone already entered their final lap? Awareness around these situations helps players make key decisions in an overall hectic environment. Knowing that their friend is in first place, for example, might give a player the inclination to throw a Blue Shell item sooner than they would’ve otherwise. On the other hand, with courses like Cloudtop Cruise where the thundercloud section of the map changes the arrangement, other players become aware of just how far behind they are from the local frontrunner when the music shifts.

Conclusion

What makes Mario Kart 8’s audio so effective is its dedication to prioritizing clarity across seemingly every imaginable scenario. This is achieved by boiling down and meticulously fine-tuning the elements that make the single-player experience successful, and then expanding on those principles in the local multiplayer mode. The core principle is that every sound-driven action that’s important to the race should be impactful and audible.

This is a foundational concept that can be utilized in multiple games, no matter the genre. The strong execution of these ideas allows a soundscape to be clear and communicative, even in the most hectic environments—like four players in a room playing a chaotic kart racer through television speakers.


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April 5, 2021

Ronny Mraz Ronny is a Technical Sound Designer at Avalanche Studios in New York City. There, he has worked on the recently released Just Cause 4, as well as the game’s three downloadable content packs: Dare Devils of Destruction, Los Demonios, and Danger Rising. He's also a member of the Adjunct Faculty at NYU Steinhardt where he teaches the class, "Scoring Techniques: Video Games."