Evaluation of Physically Inspired Models in Video Game Melee Weapon SFX

Emil Wallin

Audio Technology, bachelor's level 2020

Luleå University of Technology Department of Arts, Communication and Education

Evaluation of Physically Inspired Models in Video Game Melee Weapon SFX

Emil Wallin Luleå University of Technology [email protected]

ABSTRACT This study explored the possible impact to a game’s responsiveness and to players’ preferences by using a physically inspired model (real-time pitch and amplitude modulation) as a means of efficiently achieving responsive variation for melee weapon sound effects in a game using the in-engine audio features. A play test was created were 24 participants (12 with audio engineering backgrounds, 12 without), all with prior gaming experience, played through a game level where they would audition a non-variational implementation of a sword’s sound effects and a variational implementation with the same sound samples being modulated in real-time. The participants did not know what they were auditioning, and in a form filled out after the play test they assessed the differences in the level parts’ responsiveness and their preference. From this form no significant benefit or drawback was found to the game’s responsiveness, and no significance was found to the participants’ preference toward either sound effect implementation. The study’s conclusions are that these physically inspired models could be used as a mean of implementation for melee weapon sound effects if the sounds used or the game setting would suit this approach, or if this would be the artistic wish of the game developers.

2 TABLE OF CONTENTS 1 INTRODUCTION 4 1.1 INDIE GAMES 4 1.2 BACKGROUND 4 1.2.1 SOUND EFFECT VARIATION IN GAMES 4 1.2.2 EXTENSIVE SOUND LIBRARIES 5 1.2.3 LARGE SCALE GRANULAR SYNTHESIS 5 1.2.4 PHYSICAL MODELING 5 1.2.5 INPUT PARAMETERS OF A PHYSICALLY INSPIRED MODEL 6 1.2.6 THE MELEE WEAPON SOUND 6 1.2.7 OUTPUT PARAMETERS OF A PHYSICALLY INSPIRED MODEL 7 1.2.8 DEFINING RESPONSIVENESS 7 1.2.9 UNREAL ENGINE 4 7 1.3 PURPOSE AND RESEARCH QUESTION 8 1.3.1 REALISM IN VIDEO GAMES 8 1.4 HYPOTHESIS 9 2 METHOD 10 2.1 TOOLS 10 2.1.1 SOFTWARE 10 2.1.2 HARDWARE 10 2.2 SOUNDS AND IMPLEMENTATION 10 2.2.1 ADDITIONAL SOUNDS 11 2.2.2 IMPLEMENTATION OF THE PHYSICALLY INSPIRED MODEL 11 2.2.3 BEFORE PRE-STUDY 12 2.3 PRE-STUDY 12 2.4 MAIN STUDY 13 2.4.1 THE GAME 13 2.4.2 THE QUESTIONNAIRE 16 2.4.3 DEMOGRAPHICS 17 3 RESULTS AND ANALYSIS 19 3.1 RESULTS 19 3.2 DATA ANALYSIS OF THE RESULTS 20 3.3 DEMOGRAPHIC DATA – ANALYSIS 24 4 DISCUSSION 26 4.1 THE RESULTS 26 4.2 FROM PRE-STUDY TO RESULTS 26 4.3 RESPONSIVENESS 26 4.4 PREFERENCE 27 4.5 COMMENTS BY SUBJECTS 27 4.6 EXPERIMENT METHOD AND POSSIBLE ERROR SOURCES 28 4.7 OTHER USES FOR PHYSICALLY INSPIRED MODELS 29 4.8 ECOLOGICAL VALIDITY 29 4.9 FUTURE RESEARCH 29 4.10 SUMMARY 30 5 ACKNOWLEDGEMENTS 31 6 REFERENCES 32 APPENDIX A 34 APPENDIX B 38

1 INTRODUCTION The problem of variation in video games has been a point of interest since the hardware became capable of using big sound libraries and real-time synthesis. In the last decade these tools have also become accessible to game developers with small or no budget, but it has not yet been utilized to its full extent. The proposed research investigates the use of simple physical modelling, called physically inspired models, in video games and its possibilities regarding melee weapon sound effects, and in turn its use in indie game-development. This project will amass data from a questionnaire after a play test were a game level will be presented to test subjects who then play through different parts of the game level which utilizes different ways of implementation, and the participants later answer questions about the audio. 1.1 INDIE GAMES The last decade has seen a huge rise in indie-game sales and success, and some would argue that many of the best games of the decade 2010-2019 has been indie-titles. On Forbes’ “The Best – And Most Important – Video Games Of The Decade”-list (Kain, 2019) we see titles like Hotline Miami (Dennaton Games, 2012), Hollow Knight (Team Cherry, 2017), and Journey (Thatgamecompany, 2012) on the same list as big-studio titles (AAA titles) such as Grant Theft Auto V (Rockstar Games, 2013). The success of indie-games has brought forward certain aesthetics which are often featured through-out many titles. Most indie-titles tend to be limited in their graphical capabilities and instead prosper in their use of aesthetic choices such as being 2D, either utlizing side-scrolling or top-down-view, and using designs inspired by retro gaming, either by the use of pixel-art, or the use of mechanics made popular by 90’s games. This inspiration has affected the sound design of these games as well, with many games using chiptunes and pulling inspiration from the limited sound capabilities of early 90’s consoles, or by simply having limited sound effect variations. A big factor in this limitation is also the lack of sound designers on indie-teams – why have many mediocre sounds instead of one good and fitting sound? This is where physical modelling could help either the indie-developer designing their own soundscape or the lone sound designer creating sounds on no budget. 1.2 BACKGROUND 1.2.1 SOUND EFFECT VARIATION IN GAMES Video games have been under limitations of the hardware for most of its existence. In 2012 the eighth generation of video game consoles radically improved performance of consoles and made experiences on console and PC more similar, which in turn made it possible to increase both the used storage space of audio and the workload of audio engines. (Kypreos, 2018) (Loveridge, 2019) The improved conditions of audio performance led to an even bigger emphasis on avoiding audio repetition, but as Vachon (2009) mentions some sounds are accepted as repetitive, most notably non-diegetic sounds of menus and HUDs. However, there is also mention of how non-repetition is specifically beneficial to fighting sounds as a fighting mechanic is often a big part of the games in which it is included. (Vachon, 2009) Stockselius (2018) conducted a study comparing repetitive and non-repetitive sound design for video games where all parts of the game’s audio were either repetitive or non-repetitive. The results showed a general negative impact of repetitive sound design, and that the second most noticeable repetitiveness of the sound design was the “karaktär” (character) category which included foley

4 and SFX (in this case gunshots). (Stockselius, 2018) This further establishes the importance of variation of SFX in games. Vachon (2009) mentions a few methods to avoid annoying repetition in games. For example, the large scale granular synthesis, the use of physical modeling, and the more obvious extensive sound library approach. These are all viable methods of achieving variation, however in the context of low-budget video game development many of them might not be achievable as the limited number of sound designers and the lack of time makes recording, designing, and implementing some of these approaches impossible. 1.2.2 EXTENSIVE SOUND LIBRARIES Recording and designing a large amount of sound samples has its share of both pros and cons, however it is the most obvious solution to avoiding annoying repetition in games. A large pool of sounds for a single sound effect gives the sound designer full control of every single sound option, ensuring that every sound keeps a certain level of quality. However, the large scope of modern games means the sound designers would have to collect and create a huge amount of sounds for a large number of events resulting in a big economical strain from both recording/buying samples, but also from the sound designers’ workload increasing drastically. (Vachon, 2009) A big sound sample library would also mean that more data would have to be loaded into the unit’s RAM, which both takes time and occupies space that might be required by other parts of the game. (Vachon, 2009) 1.2.3 LARGE SCALE GRANULAR SYNTHESIS Large scale granular synthesis is a phrase used by Vachon (2009) which uses the concept of granular synthesis but with bigger grains. Vachon’s (2009) “large scale” concept can be used by separating a sound based on time and/or frequency content. For instance, Jacobsen (2018) mentions how a door opening was split into “door handle, “swing of the door”, an optional “swing sweetener”, and “end of opening” and by separating five original door sounds into these basic characteristics which were later randomly summed in the game engine the game would contain 625 variations of a simple door sound. This creates a greater amount of variation within a limited group of samples, whilst simultaneously using less RAM by not having to load a bigger audio library (which would be the result of summing the separated sounds in advance). (Vachon, 2009) In practice a melee weapon sound effect could be separated into categories such as “aerodynamics”, “impact low end”, “impact high end”, “material impact texture”, and “resonance”, where several of the sounds could be taken out of context-dependent sound pools. 1.2.4 PHYSICAL MODELING Physical Modeling is described as using parameters of the game engine to synthesize sounds which are in direct relation to the actions of the player. (Vachon, 2009) Verron and Drettakis (2012) explains this interaction within the game engine through this visualized model:

Figure 1. Recreated visualization of Verron and Drettakis' (2012) physical model.

Verron and Drettakis (2012) used this model to create a physical model for particle based environmental synthesis, however this concept is still applicable to weapon SFX as synthesized melee weapon sounds are an explored possibility in concepts such as modal synthesis, and could by extension possibly be implemented in a real-time physical modeling setting. By implementing parameters for weapon velocity, surface/weapon type and its properties, angle and velocity of impact, etc. a realistic physical model for melee weapon SFX could be created. The study (Verron & Drettakis, 2012) does not use synthesis in a way which full physical modeling entails, instead it uses samples which are altered based on the input from the game engine. This is called physically inspired controls. (Verron & Drettakis, 2012) This can in turn be called a physically inspired model, which is what this bachelor’s project will utilize to achieve variation. In figure 1 this model can be seen in a bigger setting. The significant parts in this study are the synthesis parameters, which are variables sent between the graphics and audio engines. These variables are derived from different parts of the graphical assets, and could be user defined variables such as material, or variables calculated from player interaction such as velocity and trajectory. These variables can then be implemented in the opposite engine, deeply involving the two engines and allow the visuals and sounds to correspond more. In this study the graphics engine will be sending variables to the audio engine. 1.2.5 INPUT PARAMETERS OF A PHYSICALLY INSPIRED MODEL A physically inspired model would need to receive certain parameters from the game engine, as mentioned by Verron and Drettakis (2012). These parameters could be seen as input parameters as they are dependent on the interaction of the player. Parameters that could be used in a physically inspired model are velocity of the graphical asset, the material being struck, and angle of impact. 1.2.6 THE MELEE WEAPON SOUND There are several components to a melee weapon hit that can be subject to variational sound design. It can be divided into three main parts: Aerodynamics, Weapon, and Material, and two of these can be divided into even smaller parts: Weapon Hit, Weapon Resonance, Material Hit, and Material Resonance.

6 1.2.6.1 AERODYNAMICS The aerodynamics of a weapon sound effect includes the swing of the weapon. Dobashi et al. (2003) studied the use of real-time calculations and synthesis of weapon aerodynamics in video games and wrote how the aerodynamics of a weapon is made up of aeolian tones and cavity tones. Aeolian tones are created from stick-like objects travelling through any kind of fluid (including air), and cavity tones are created as fluids travel around the different hollows of an object. (Dobashi et al., (2003) Although no real-time synthesis will be used in this research, Dobashi et al. (2003) also mention how the frequency and amplitude of melee weapon aerodynamic sounds depend on the velocity of the weapon through air, which in turn could be simulated by the physically inspired model to be used. 1.2.6.2 WEAPON SOUNDS As mentioned, the sounds which the weapon excites can be divided into two distinct parts: The hit, and the resonance. The hit will be a basic sound consisting of a transient and a minimalistic residual component. This sound might be subject to frequency content manipulation as part of the physically inspired model. The resonance will consist of sinusoidal tones which would be created from metal being struck, and its amplitude might be the most obvious parameter to be altered. To make all of these sounds a part of the research a sword will be used as the melee weapon. It will have a hit sound, and a resonance as it would be made of metal. 1.2.6.3 MATERIAL SOUNDS The material sounds consist of the same kind of sounds as the weapon sounds; however, these sounds are dependent on what is being struck by the weapon. That would be the most prominent input parameter and would also be something that decides if a resonance would even be played, as certain materials would not resonate when struck. If this resonance part would include any residuals of the material being struck is unclear, but it is certainly a possibility. 1.2.7 OUTPUT PARAMETERS OF A PHYSICALLY INSPIRED MODEL The output parameters are parameters of anything that affects how a sound is played back in the game engine’s audio engine. A single input parameter might also interact with more than one output parameter and vice versa, and this might happen differently in different sound parts. Output parameters to be connected to input parameters might be amplitude, pitch, filter frequency (controlling frequency content), distortion amount, or any effect amount (reverb, delay, etc.). 1.2.8 DEFINING RESPONSIVENESS A common definition of responsiveness is a technical one, which can be found in articles and research of a more technical approach. West (2008) describes this definition in terms of response time, and how a slow response time to inputs cause a “sluggish” feeling within the game. This study uses a different definition of responsiveness which adheres to its connection to interaction, which in turn is a benefit of the game medium. The definition of responsiveness is not connected to how fast the sound is played when an input is done, but rather if the sound being played feels connected to the input by the player. 1.2.9 UNREAL ENGINE 4 Unreal Engine 4 is a game engine created by Epic Games (2020), and it is one of the most popular game engines (Toftedahl, 2019) used by indie and AAA developers. It has a blueprint

7 visual scripting-system which enables users to bypass coding almost completely. This makes the engine easy to use for beginners, and by using Epic Games’ first person-preset a lot of basic elements such as character textures and movement inputs are already added to the level. The Epic Games Launcher (Epic Games, 2020) also has a marketplace dedicated to Unreal Engine 4 assets, where free assets for weapons, enemies, and level design textures can be found , which enables one to build a test level quickly without having to create any textures. The engine allows for easy variable variation in all sound files, which can be directly linked to variables within the game engine. The assets to be used in the game level are “Free Fantasy Weapon Sample Pack” by Prop Garden LLC (2018), “Infinity Blade: Adversaries” by Epic Games (2015), “Medieval Dungeon” by Infuse Studio (2019), and “Soul: Cave” by Epic Games (2018). The use of velocity in Unreal Engine 4 does not have any correlation to real life, as the unit “Unreal Units” is used to measured distance, and velocity is done calculating movement over frames. The velocity of the sword has a big span and will thus be divided and clamped (divided to be made into smaller values and clamped to put limits on smallest and largest values). Through packaging a project with Unreal Engine 4 the game can be opened and played without the need of having the engine itself installed. This allows for sending the test’s game level to anyone willing to participate in the study but who is unable to participate on location. 1.3 PURPOSE AND RESEARCH QUESTION The video game industry is made up of many independent developers who produce excellent games that in entertainment value compete with the biggest AAA titles. What has developed well is the highly stylized visuals and gimmicky mechanics which makes low-budget games give high-quality value, and to further develop the quality of these games’ audio might be the next step. However, to achieve a great impact on this scene a solution requiring minimal effort to attain big rewards must be found, and physically inspired models might be this solution. The question in turn is if the implementation of a physically inspired model is noticeable and if it gets a positive response from players. Responsiveness of a physically inspired model and the players response to this has to be researched, and in turn preference can be found in the same experiment. The aim of this research is to find if a physically inspired model applied to weapon SFX achieves a difference in perceived responsiveness, if it is noticeable, and if there is a preference by video game consumers. 1.3.1 REALISM IN VIDEO GAMES This experiment does not tackle the use of physically inspired model to achieve realism. The experiment’s goal is to find if physically inspired models can be used simply to enhance the experience audio brings to indie games, if the experienced responsiveness is heightened and if this is perceived as a positive aspect of the game. In video games realism is not an aspect that is always sought after, as long as suspension of disbelief is achieved. Suspension of disbelief is a concept in which the reader, watcher, or in this case player immerses themselves into the experience. Phillips (2014, p.36) writes how suspension of disbelief is a willing acceptance of outlandish aspects and is a way to appreciate fantastical works. The audio’s mission is to not break this suspension of disbelief, and rather than being “realistic” it simply has to be believable and acceptable in the context, hence this will be researched as well; is the sound design acceptable in and indie game-setting?

8 1.4 HYPOTHESIS The hypothesis is that the use of a physically inspired model can achieve a greater experienced responsiveness in weapon sound effects, and that this would be preferable to video game consumers. There are instances were audio middle-wares use this kind of audio implementation, however, an in-engine solution to achieve variation in video game sound effects, foley, and any other sound in which variation and responsiveness is wanted could give indie game-developers the tools to achieve better audio in their already great games.

The nullhypothesis (h0) of the study is that there is not any advantage in responsiveness or preference in using a physically inspired model for melee weapon sound effects. This is expressed as:

ℎ0: 푀 = 휇 = 0 Were M being the mean of the sample group and µ being the population’s mean. There are two alternative hypotheses for this study: h1 and h2. These will cover the second and third possible outcome of the study’s results, which are that there are disadvantages to the physically inspired model’s implementation (h1) or that there are advantages to the physically inspired model’s implementation (h2):

ℎ1: 푀 < 휇 = 0

ℎ2: 푀 > 휇 = 0 All of the three hypotheses will be tested for both responsiveness and for preference. These will be noted as h0R, h1R, and h2R for the responsiveness, and h0P, h1P, and h2P for the preference. Four t-tests will be done to test the significance of the gained data. Two one-sample t-tests to test the responsiveness and the preference, and two independent t-tests to test the same data divided into the two test groups: Audio engineers and non-audio engineers. These final t-tests will determine if the difference between the two groups’ ratings are significant, finding if an audio engineering background contributes to the perception of melee weapon SFX in video games. The calculated t-values will then be compared to the critical t-value which will be sourced from a table. Additionally, P-values will be calculated, which will help to show the possible significance of the results, as a P-value below 0.05 would mean the results have statistical significance.

9 2 METHOD To attain the game level and the full soundscape needed to complete the test and to reach the wanted ecological validity a game engine and a digital audio workstation was needed. In Unreal Engine 4 (2020) all wanted parameters for the physically inspired model is present and in its marketplace there are free graphical assets available which was optimal for time management. For sound designing any DAW would have sufficed, however Reaper 6 (Cockos, 2020) was chosen based on prior experience with the software. Shadowplay (Nvidia, 2020) was chosen as it is directly extracted from the graphics processor of the computer used for testing and does not affect performance of the game. Additionally, all hardware was chosen based on accessibility and its capability to run the game level. Test subjects participating from home were told to record their screens and audio, and to do so they could use any software which worked well with their computer. They were also told to preferably use over-ear headphones intended for studio, hifi, or gaming use, as this would be ecologically valid options while still being a decently controlled form of listening (no need to worry about correct speaker placement). 2.1 TOOLS The tools used in the experiment were: 2.1.1 SOFTWARE Unreal Engine 4 (Epic Games, 2020) – Game Engine Reaper 6 (Cockoc Inc. 2020) – Digital Audio Workstation Nvidia Shadowplay (Nvidia, 2020) – Recording software 2.1.2 HARDWARE Headphones (Beyer Dynamic DT770, or other if the test is completed through distant testing) PC (Computer with a Windows (Microsoft, 2020) operating system) Keyboard and Mouse 2.2 SOUNDS AND IMPLEMENTATION The implementation of sounds and the physically inspired model were all done in-engine, and thus it could be easily adjusted. The weapon sounds were all created in Reaper through a mix between recorded material and sounds from a sound effects library. These were split into three separate parts: Aerodynamics (for two variations of sword swings which were used for all attacks), a residual of the aerodynamics if nothing was struck by the sword during the attack, a hit for three different materials (rock, enemy, and metal), and residuals for two of the hits (rock and enemy, as the metal hit already had a prolonged resonance within the hit). The material and sword sounds (hits and residuals) were combined, as this was found to give a satisfying result both with and without the physically inspired model.

10 2.2.1 ADDITIONAL SOUNDS To achieve a greater ecological validity a complete soundscape in addition to the weapon sound effects was created. This included:

• Footsteps and foley • Sound effects of enemies (footsteps and grunting) • Ambience/Environmental sounds • Simple music These were mixed to not be put in focus as to not obstruct the weapon sound effects. They were also designed with minimal variation as to not affect the participants’ experience. 2.2.2 IMPLEMENTATION OF THE PHYSICALLY INSPIRED MODEL The physically inspired model, or rather models, were created in Unreal Engine 4 (Epic Games, 2020) through the use of a blueprint node within their “Sound Cues” called “Continuous Modulator” which modulates pitch and amplitude in real-time based on an input float variable. This variable was derived from the sword’s tip’s velocity. The velocity was also clamped between min and max input values, and these values were scaled to the min and max output parameters to decide how much the sound was to be altered. Different parameter modes were available which handles the input of the variable differently. The blueprints for this was setup as in figure 2 below:

Figure 2. The sound cue blueprint for the enemy hit, here called HIT_FLESH. The same structure and setup was used for all sounds.

The different parts of the sounds were varied differently, and the list of how they were varied can be seen in table 1 below.

Table 1. Table of how each weapon sound was altered in-engine. SOUND PITCH MOD. AMPLITUDE MOD. Input Parameters Aerodynamic LEFT Yes Velocity Aerodynamic RIGHT Yes Velocity Aerodynamic RES Yes Velocity, No material Rock HIT Yes Yes Velocity, Material: Rock Rock RES Yes Yes Velocity, Material: Rock Enemy HIT Yes Yes Velocity, Material: Enemy Enemy RES Yes Yes Velocity, Material: Enemy Metal HIT+RES Yes Yes Velocity, Material: Metal

11 Aerodynamics “LEFT” and “RIGHT” were determined by the mouse button inputs, and “RES” was short for “residual”/”resonance” in all cases. When an attack was triggered the corresponding aerodynamic sound was played, and the sword checked for collision with any material which decided which kind of hit and residual was played, if no material was found the aerodynamic residual was played. 2.2.3 BEFORE PRE-STUDY Before the pre-study was done a game level, modeled as a dungeon, was created, and a complete soundscape was created. This soundscape was intentionally made to sound non-variational and “sterile” as to not draw too much attention from the weapon SFX. A complete set of sword sound effects with aerodynamics, metal hit, stone hit, and enemy hit sounds were created and implemented. The physically inspired model was also implemented and used on these sounds, and a simple boolean variable was set up to determine the model’s implementation, which meant that both non-variational and variational sound effects could be utilized within the same game level. The damage output from the sword hitting enemies were also made to be decided by the sword’s velocity, which in turn would give meaning to the players experiencing the modulating sounds. 2.3 PRE-STUDY The pre-study was done to determine the extent of the physically inspired model and to gain input on the weapon sounds themselves. This was done through listening tests with four audio engineers who have taken a video game audio course, and who regularly play video games. The pre-study was also separated into two meetings to add changes suggested from the first meeting and gain additional feedback during the second meeting. Some additions from the pre-study discussions were the aerodynamic residual, added resonances (sinusoidals) to the aerodynamic sounds, the removal of a sword resonance from the enemy residual sound, and the addition of the metal hit. Several bugs were found during testing, and an additional tutorial section was added to the beginning of the test to teach participants how the damage output (and audio) responds to player interaction. Additionally, the damage was sectioned into three constant damages to give a more consistent response to the player movement. This was done through rounding damages within ranges to output the damages 10, 20, or 40, which were also shown on-screen. The settings for the “continuous modulators” used can be found in the table below. However, these settings are highly dependent on the sounds used and the settings would need to differ in other experiments. The “Parameter mode” was set to “normal” for all sounds, which does not alter the handling of variables in any way (the variable is directly put through to the min and max output and is not scaled or altered to fit).

12 Table 2. Table of the Continuous Modulator settings of each sound's Sound Cue. Pitch Modulation Amplitude Modulation Sound\Setting Min Max Min Max Min Max Min Max Input input Output Output Input Input Output Output Aero Left 150 500 0.8 3.5 - - - - Aero Right 150 500 0.8 3.5 - - - - Aero Res 150 500 0.8 3.5 - - - - Rock Hit 100 400 0.8 1.5 200 400 0.9 1.3 Rock Aftermath 100 400 0.8 1.5 200 400 0.9 1.3 Enemy Hit 100 400 0.7 2 1 300 0.9 1.3 Enemy Aftermath 100 400 1 1.5 100 400 0.9 1.25 Metal hit 100 400 0.8 1.5 200 400 0.9 1.3

2.4 MAIN STUDY The main study was divided into two sections: The game and the questionnaire. The game explained the experience of the tester as they played through the game level, and the questionnaire explained the different questions asked after completing the game level. Before each test subjects’ participation, they were given the option to adjust the sound level of the game and were then given instructions on how the experiment would play out. The instructions covered the different parts of the game level, the order of these parts, and how to exit the game to gain access to the form. 2.4.1 THE GAME The game level started off with a short tutorial-section explaining the basic controls, as well as letting testers experience the sounds of the two different wall hits as two walls will be needed to be struck during the traverse of the tutorial section. In the end of the tutorial section a troll texture was placed as a dummy enemy to teach players how to achieve different amounts of damages, and unless the dummy was hit for 10, 20, and 40 damage the door to exit the tutorial section would not open. There were visualizations of the three different damage tiers on the walls next to this door which lit up and played a sound effect when the damage tier had been struck. The tutorial section did not utilize any variational sound design.

Figure 3. The first room of the tutorial section of the game level.

Figure 4. Second room of the tutorial section of the game level.

Figure 5. The third and final room of the tutorial section of the game level.

The main part of the game level was comprised of two portals, named Test 1 and Test 2 (which could be seen in-game), which teleported the player to the test’s play area where enemies spawned. The portals decided, while teleporting the player, if the weapon SFX physically inspired model was to be enabled or not. Through doing this the order of the test could easily be changed by making either portal activate the physically inspired model. The tester was allowed 90 seconds in the test area before being teleported back to the portal room, where the next part of the test could be started (which had the same time limit). As the two different tests of the game level could be changed to be variational or non-variational this was alternated between test subjects. Half of the test subjects would experience the non-variational sound design first, and the variational sound design second, and the other half would experience the opposite order. A solution to how the questionnaire would be done was found, as one test subject would experience variational sound design as “Test 1”, while another would experience “Test 1” as non-variational. This is explained in “The Questionnaire” part.

14 Figure 6. View of the portal room as seen when entering from the last room of the tutorial section.

Figure 7. Bird's-eye view of the test room. Enemy Spawn is the point where new enemies will appear. Player Spawn is the point where the player will teleport to as they enter the portals.

Figure 8. The room where the testing will be done. Both parts of the experiment take place here. The white rectangle on the left side is a hitbox for the metal prison cell wall also seen in figure 2.

The enemies which spawned into the map were small “Gruntlings”, which is a free game asset part of the “Infinity Blade: Adversaries” (Epic Games, 2015). These played a sound when hit, and a longer sound when killed to annotate to the player whether the enemy was killed or not, and this sound is the same in both tests and are unaffected by the physically inspired model. 2.4.2 THE QUESTIONNAIRE The questionnaire was answered after the test was completed, and consisted of comparisons between the two tests (variational vs. non-variational), and some demographical questions regarding the testers’ playing habits which could have proven useful in discerning trends relating to their comparison ratings and answers. The two comparisons made were the two versions’ responsiveness (alluding to the player’s velocity input and the audios’ response in to it) and their preference, which was asked to find which kind of sound implementation was preferred, or if it did not matter. A question regarding if the weapon sound effects of any test would be acceptable for an indie title was asked for additional data on the sound design, and an additional question asking them to further explain why or why not this would be the case was asked to give further insight in their reasoning. All comparisons and questions were done in Google Forms to easily be compiled and compared after the completed tests. Two different forms (A and B) were made which were intended to be used depending on which order the test subject had experienced the game level as to not mix which sound design they experienced as Test 1 and Test 2. Form A was to be answered by test subjects who played the game level where Test 1 had non-variational sound design, and form B was to be answered by test subjects who played the game level where Test 1 had variational sound design. The answers of the forms would later be compiled and analyzed in Microsoft Excel, where the ratings for form B could be reversed. The ratings were changed to a value between -2 and 2, where 0 was no difference perceived/no preference, and -2 meant much more responsive/preference towards the non-variational sound design, and 2 meant much more responsive/preference towards the variational sound design, with increments of the ratings written as -1 and 1.

16 A one-sample t-test was done which would have had to achieve a statistical significance with a probability of 훼 = 0.05. The complete number of subjects was 24, which made 푁 = 24. This made it possible to calculate the degree of freedom (df) to: 푑푓 = 푁 − 1 = 24 − 1 = 23 By using a table of critical t-values the critical t-value was found to be 2.069 for the degree of freedom of 23. (Richland Community College, 2020) Within these 24 test subjects 12 were or are studying/working in any field of audio engineering, and 12 had no background in audio engineering, which gave 푁퐴 = 12 and 푁푁 = 12. The comparison between the two groups was done using an independent t-test and a probability of 훼 = 0.05 was used as well. The degree of freedom for the independent t-test could be calculated as:

푑푓퐶 = 푁퐴 + 푁푁 − 2 = 12 + 12 − 2 = 22 By using a table of critical t-values the critical t-value was found to be 2.074 for the degree of freedom of 22. (Richland Community College, 2020) 2.4.3 DEMOGRAPHICS The participants of the study were all aged between 20 and 30 and had prior gaming experience. As mentioned before half of the participants had audio engineering experience through being audio engineering students, and the second half had no experience with audio engineering experience and were either studying or working in unrelated fields. Additional demographic data of the participants can be found below.

Table 3. Table of the genre preference distribution of the participants. Genre No. Of Subjects Action/ Adventure/Action-Adventure games (not including RPG-games) 7 FPS - online or otherwise (First-Person Shooter) 7 MMO - MMORPG or otherwise (Massively multiplayer online games) 4 Other 2 RPG (Role-Playing Games) 2 Sports games 1 Strategy games 1

17 Prior indie game experience

About half of the games I play are indie titles I play indie titles occasionally

I never play indie titles

Not sure

0 2 4 6 8 10 12 14

Figure 9. Diagram of the distribution of prior indie game experience.

Preference of controller type

Keyboard and Mouse

Equal/No difference

Controller (Any Controller)

0 2 4 6 8 10 12 14 16

Figure 10. Diagram of the distribution of controller type preference.

Table 4. Number of subjects divided into the amount of time spent playing video games (on average) each week. Hours No. Of Played Subjects 0-5 h 13 6-10 h 2 11-15 h 4 16-20 h 1 20+ h 4

As can be seen in table 4 13 participants play 0-5 hours a week, and as this is a substantial part of the group’s composition tests will be done to find trends in this division of the group.

18 3 RESULTS AND ANALYSIS A total of 24 subjects participated in the experiment: 12 audio engineering students and 12 people either working or studying in branches unrelated to audio engineering, however, all subjects had some experience playing games. Some of these participants completed the test on their own computers but were given a document with instructions on how to proceed with the experiment, to record both screen and audio, and a link to their experiment’s corresponding form. 3.1 RESULTS The questionnaire answers are compiled and presented in different tables to make comparisons easier and make the data easier to examine. The qualitative data collected were partly in Swedish and have been translated as needed and summarized to make easier comparisons. The full answers can be found in Appendix B. The comparisons have been given values between -2 to 2 as mentioned in the method. The mean and median will be presented in the tables, and additional graphs will be used to visualize the distribution of the answers in the header 3.2.

Table 5. Compilation of all comparisons of responsiveness and preference made by test subjects. The last column signifies if the test subject studies/works in audio engineering or not. Subject Responsiveness Preference Audio/Not 1 0 0 A 2 1 1 N 3 1 1 A 4 2 1 A 5 0 0 N 6 -1 0 N 7 1 1 A 8 0 1 A 9 2 0 N 10 0 0 N 11 1 1 A 12 1 1 N 13 0 0 A 14 0 1 A 15 0 0 N 16 -2 -1 N 17 0 -2 N 18 0 0 N 19 0 0 N 20 0 0 A 21 -1 -1 A 22 1 1 A 23 0 0 N 24 -1 -1 A

MEAN: 0.20833 0.16667 MEDIAN: 0 0

19 The question regarding which test’s sound design would be fitting for an indie title resulted in the answers seen in table 5.

Table 6. The data collected from the tests identifying if the sound design would be ecologically valid or not. Answer No. Of Subjects Var 2 Non-var 3 Both 12 Neither 1 Not Sure 5

3.2 DATA ANALYSIS OF THE RESULTS

Responsiveness Comparison Ratings

8 No. No. Of Subjects 6

0 -2 -1 0 1 2 Ratings

Figure 11. Histogram of the distribution of the responsiveness comparison ratings.

20 Preference Comparison Ratings

6 No. No. Of Subjects

0 -2 -1 0 1 2 Ratings

Figure 12. Histogram of the distribution of the preference comparison ratings.

Below is a list of the subjects’ abridged and translated comments regarding responsiveness and preference. Full untranslated comments can be found in Appendix B. Non-variational and variational sound design indicates the use of the physically inspired model.

Table 7. Compilation and abridgment of comments made by test subjects about the two tests. About Non-variational Sound Design About Variational Sound Design Faster response from attacks Better damage and strike response Smoother Better responsiveness Meatier sounds. Bigger effect. Gentler Brighter and perceived louder. sound Satisfying. More responsive. More realistic. More Responsive More variation Felt faster and more responsive Bigger involvement Faster pacing by the sound/attack Brighter. Felt faster. Faster and more engaging. More dynamic. Faster More realistic. More realistic. Not delayed More immersed Easier recognition of damage. Chaotic Higher pitched - irritating when repeated. Felt clumsy. Less wet. More realistic.

21 Table 8. Ratings ordered from low to high, and analysis of all values can be found in this table. Comparison: Responsiveness Preference -2 -2 -1 -1 -1 -1 -1 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 2 1 MEAN: 0.20833 0.16667 MEDIAN: 0 0 Standard 0.93153 0.81650 Deviation: Variance: 0.86775 0.66667 T-test: 1.09563 1.00000 P-Value: 0.28458 0.32772

Table 9. Responsiveness ratings divided into subjects with audio engineering backgrounds and subjects without said background. Independent t-test and P-value has been calculated along with standard deviation and variance. Responsiveness, Responsiveness, Comparison: Audio Engineers Non-Audio -1 -2 -1 -1 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 1 1 1 2 2 MEAN: 0.18182 -0.09091 MEDIAN: 0 0 Standard Deviation: 0.75076 0.83121 Variance: 0.56364 0.69091 T-test: 0.84348 P-Value: 0.40804

Table 10. Preference ratings divided into subjects with audio engineering backgrounds and subjects without said background. Independent t-test and P-value have been calculated along with standard deviation and variance. Preference, Preference, Comparison: Audio Engineers Non-Audio -1 -2 -1 -1 0 0 0 0 0 0 1 0 1 0 1 0 1 0 1 0 1 1 1 1 MEAN: 0.36364 -0.18182 MEDIAN: 1 0 Standard Deviation: 0.80904 0.75076 Variance: 0.65455 0.56364 T-test 1.71196 P-Value: 0.10097 All t-tests and P-values show that there is no significance to the difference between audio engineers and non-audio engineers, as well as there being no significance to the found mean of all responsiveness and preference ratings. Thus, the null hypotheses h0R and h0P can both be accepted.

23 3.3 DEMOGRAPHIC DATA – ANALYSIS Most of the collected demographical data did not show any significance in the distribution, however the data of the hours played weekly showed a group of 13 played 0-5 hours weekly, which makes further analysis possible. In figure 13 the means of both responsiveness and preference ratings can be seen divided into the different times played.

Means of Responsiveness and Preference ratings divided into weekly hours played 1,5

0,5

0 0-5 6-10 11-15 16-20 20+

Mean of Ratings -0,5

-1 Hours Played Responsiveness Mean Preference Mean Figure 13. Diagram of the mean of both ratings of each group based on hours played.

This diagram shows lower ratings as playtime increases; however, most of these groups should be considered too small for an accurate representation of the population. As only one group (0- 5 hours) reached enough number of subjects to be individually analyzed its results will be analyzed in full while the other groups will not be analyzed further.

Table 11. Analysis of the ratings from the group of participants who played 0-5 hours weekly. Comparison: Responsiveness Preference -1 -1 -1 -1 -1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 2 1 MEAN: 0.23077 0.30769 MEDIAN: 0 0 Standard Deviation: 0.92681 0.75107 Variance: 0.85897 0.56410 T-test: 0.89776 1.47709 P-value: 0.38697 0.16541

24 The t-tests and P-values show a statistical insignificance for both the responsiveness ratings and preference ratings. They cannot be seen as an accurate representation of the population playing 0-5 hours of games a week.

25 4 DISCUSSION 4.1 THE RESULTS As seen above the results show no significance to the found mean. The mean of both the responsiveness and preference (table 3) are close to the null hypothesis’s mean of 0, and not finding any significance in these results was not surprising. Both figure 8 and figure 9 show a majority of test subjects either did not notice any difference between the two tests or could not distinguish any difference in responsiveness or find a preference in the difference between the two tests. However, in studying the preference the majority of subjects either had no preference or had a small preference towards the variational sound effects. 4.2 FROM PRE-STUDY TO RESULTS During the pre-study testing phase all present audio engineers noted that there was a clear difference between the non-variational and the variational sound effects. During the pre-study meetings tests were done to be sure that the sounds worked in both variations of the implementation and that the sounds lived up to a certain standard of sound design to achieve an ecological validity in the main study. This did not translate to the results of the experiment as several subjects stated that they did not experience any difference between the two tests. Conclusions from these results could be that people do not pay much attention to sound effects in video games, or that they would need to familiarize themselves with a game’s sound effects for a longer duration to be more susceptible to minor changes which the physically inspired model introduced in this experiment. The problem with identifying any difference between the tests, while this was clearly identifiable during the pre-study could be due to the pre-study participants being aware of how the sound effects were altered and what to listen for, while the participants of the main study were not told what to listen to and would then maybe be distracted by other elements of the game, such as foley, atmosphere, music, or any other sound part of the game level. Even though these were made to be sterile and free from variational elements there were comments made about sounds which were the same throughout the whole experiment. This might be due to the sound being experienced differently in the two different tests as a result of the test subjects’ way of playing. As games are an interactive medium there is no telling how the test subjects play and move through the level, and a solution to this could have been to streamline the test even more and limit the players’ movement. However, this would remove a big part of the medium’s interactivity, severely compromising ecological validity and removing a core part of what defines the modern video games which this study intended to emulate. Another solution would have been to remove all sounds which are anchored to the game world, such as all foley, and all atmospheric sound effects. This was decided against, as this also would have compromised the ecological validity of the experiment and would give the test subjects an experience which is inherently not game-like. It would also have given an unfair representation in which the effect of the physically inspired model on a single sound effect would have been investigated instead of its effect on the game as a whole. 4.3 RESPONSIVENESS The results of the responsiveness comparison showed that no significant advantage or disadvantage could be found. This could mean that the use of a physically inspired model on melee weapon sound effects is not the optimal usage of this model. The games general responsiveness might benefit more from giving other interactive elements this treatment, such

26 as throwable or movable objects’ sounds reacting to the speed of the thrown/moved objects. Another question which has to be asked is if this is the way to raise responsiveness of the game, or if there are better ways to do this. 4.4 PREFERENCE The results of the preference comparison showed that no statistically significant preference could be found, and the mean of all participants preferences were even closer to none than the mean of the responsiveness. It is possible that this result would be due to some people hearing a difference, and experiencing a difference in responsiveness, but not finding a preference between the two tests. In figure 9 we see that 20 of all 24 participants either did not have a preference or found a slight preference towards the test with the physically inspired model implemented. This could be seen as there being no drawback to using this model, as most people will like it or don’t care either way. However, the results from the experiment is clear and, similar to the conclusion related to responsiveness, melee weapon sound effects might not be the category of sound effects most suited for physically inspired models. Another possible issue is that the implementation of the physically inspired model was imperfect and would need to be done in another fashion with different sounds, different parameters, or based on different game engine variables. The implementation of this also might not be something that should be at the forefront of the soundscape, but rather something subtle that is not in itself noticed but would work well when playing simultaneously as other sounds in the game, slightly separating it from the non-interactive sounds. 4.5 COMMENTS BY SUBJECTS Several comments were made by participants which not only mention how they experienced the responsiveness of the tests, but also other factors which would impact their decisions on how they view the responsiveness and what made them prefer one test over the other. There were two comments mentioning a superior responsiveness for the non-variational test, and four that mentioned a superior responsiveness for the variational test. However, there were comments made that could allude to the idea of responsiveness, such as how the variational test “felt clumsy”, which could be due to the possibility for lower-pitched sounds than the non- variational test, and how it had an “Easier recognition of damage”, which sounds like a connection made between the pitch of the sound to the damage output. The non-variational test was also described as smoother, which could be due to the sounds used for the attacks being designed to sound good when played back at a non-variational pitch. It would be easier to guarantee a “smoother” experience when there are no variations to take into account. The same test’s sounds were also described as “meatier”, having a “bigger effect”, and “satisfying, which could be due to the attacks of the variational test being pitched up, essentially moving the low- frequency content and making the attacks feel “lighter”. This could be amended by adding a low-frequency sound which would play in tandem with the pitched sound, but the sound itself would not be affected by the physically inspired model. There was also a comment mentioning how the non-variational test had “more variation”, which is not true as it was the same sound playing every time, but it might have been perceived that way, or simply have been a mix-up when filling out the form. The variational test was described as more realistic a total of three times, which could hint to a more advanced physically inspired model’s use as a fully realistic simulation of melee weapons. The variational test was also described as “faster” or feeling faster four times, which would be due to the pitch modulation in Unreal Engine 4 (Epic Games,

27 2020) not doing a granular pitch-shifting, but rather using a pitch-shifting algorithm which changes the length of the file to achieve the desired pitch. This creates a problem with the sounds’ timing, and there might be solutions through using an audio middleware that uses a different pitch-shifting algorithm which would keep the timing unaltered. Analyzing the data differently, in quantity rather than quality, we can see that the variational sound design was commented on more times than the non-variational, a total of 19 times in comparison to 6 times for the non-variational sound design. This might mean that the variational sound design is seen as the non-standard version of sound design and might be something different for the participants. However, as mentioned before the tutorial section was using the non-variational sound design which might, and probably has influenced this greatly. Looking at the amount of comments for either version also shows that, although several people mentioned not finding any difference and comparison ratings being statistically insignificant, the ones who heard a difference often connected it to the test with the physically inspired model, which might suggest that in some cases the difference was heard but it could not be categorized as a benefit or a drawback to responsiveness and preference. 4.6 EXPERIMENT METHOD AND POSSIBLE ERROR SOURCES There are several error sources in both the way the physically inspired model was implemented, and in some parts of the experiment as a whole. First and foremost the pre-study model used to find fitting sounds and parameters for the physically inspired model would have attained better results if it included a blind test instead of having audio engineers who knew about the model decide its range and how it would sound. Ideally a test similar to the main study would have been better to find parameters which probably would have minimized the number of participants of the main study who could not notice any difference between the two tests. Additionally, the sounds in this test were not created by an experienced professional sound designer, but rather an audio engineering student. The professionally sound designed sounds might have offered a higher ecological validity and sounds that maybe would have worked better with the physically inspired model. A possible solution to this could have been to invest in professionally designed sounds from a sound library, however this would not have given the same kind of freedom in designing the sounds around the needs of the experiment. One of the biggest error sources is the mix up of test 1 and test 2 when answering the form. As the differences between the two tests are quite small in the context of the game level a problem with keeping the two experiences separated would be problematic when answering the form, as the form is answered once the game level is completed, and as it does not describe either test (only described as Test 1 and Test 2) it might be hard to remember how they experienced the Test 1, or how the two tests were different. There are also other terms which might have given a more defined answer. “Responsiveness” might not be something that people playing the game thought they would be comparing, and thus it might have been hard answering that question. Telling test subjects what they would be comparing might have impacted how they played the game and how they experienced the game, which made this solution unviable as the goal was to see a true advantage or disadvantage of the model which would not have happened if the participants changed how they played the game. Another error source for the local tests is that the participants played the game on unfamiliar hardware and would not be able to change the sensitivity of the mouse, and the keyboard was a mechanical keyboard which maybe not

28 everyone is used to. This definitely impacted how familiar the participants felt with the game, and how fast they familiarized themselves with the mechanics, and people participating in the study from home would have an easier time with grasping the mechanics and getting an overall better experience. 4.7 OTHER USES FOR PHYSICALLY INSPIRED MODELS As Verron and Drettakis (2012) used the physically inspired model for particle-based environmental effects, other uses for this kind of model could very well be preferred. There are two main reasons as to why this would be used, which are time saving and interactivity. For instance, if stones would fall, with different velocities, during different parts of the game, then it might be easier to simply connect one sound to all individual stones’ impacts and modulating the sound based on the stones’ velocities rather than creating tens or hundreds of different stone impact sounds. This would save both time, as the creation and implementation of every sound would have to be done individually, and memory, as the total file size of all sounds would be significantly smaller. The other reason, interactivity, is in part due to the unpredictability of players’ actions, and if an object can be moved or thrown it has the possibility to do so with velocities between zero and a developer-defined maximum. Due to the aspect of interactivity every velocity cannot be represented by a unique sound, and to combat this the sound used could use a physically inspired model to react to the object’s velocity to create the perception of an infinite amount of sound variations. There are several uses of physically inspired models which will be both game- and sound-dependent, and they are almost certainly used in several games without being defined as physically inspired models. As Vachon (2009) mentioned, avoiding tedium and making the game’s sound non-intrusive to the experience, there are long-term benefits to using variational sound design where sounds which might have been found annoying without any kind of variation can be found to still be enjoyable and beneficial to the experience after several hours (sometimes tens or even hundreds of hours) of playtime. Finding these kinds of benefits require huge commitments from both the researchers and the participants, and it might not even be a realistic expectation for anyone to ever accomplish such a study. 4.8 ECOLOGICAL VALIDITY The study put a big focus on ecological validity, and the goal was to test a realistic gaming scenario where the physically inspired model was tested in a setting which would not increase the impact due to isolation of the affected sounds. Through using a full soundscape and not giving away the affected sounds a true improvement or deterioration to the gaming experience could be found. If the influence of the physically inspired model would have achieved a statistical significance, then this could have implied a benefit which would directly carry over to a “real” game setting rather than only being applicable in an experiment setting. As the results show an insignificant benefit to the game’s responsiveness and to the general preference of the population representation it could be said that there would be no significant benefit to a real game’s responsiveness or reception of the public by adding a physically inspired model to the melee weapon sound effects. 4.9 FUTURE RESEARCH In the future there are several possibilities to discover good uses for physically inspired models. This includes doing additional testing to the experienced responsiveness and player preference

29 by using different sounds, different weapons, and different parameters, perhaps even using different means of implementation. The use of physically inspired models is highly situational and thus the results would possibly be different when small parameter changes are made. Similar settings as this test might also have benefits which were not studied in this experiment, such as realism, or immersion, and this presents additional research questions to study in the future. There is also future research in using physically inspired models in different sound effect categories, as Verron and Drettakis (2012) used it for environmental sounds there are several other sound effects which might benefit from using a similar model, and this might be especially true for games in another format. As first-person combat did not give any significant benefit there might be benefits to using physically inspired models for different sound effects in a different video game genre. 4.10 SUMMARY In summary the study did not find any statistically significant benefit or drawback from using a physically inspired model for melee weapon sound effects. This means that a physically inspired model could be used (depending on context) in a project to attain a wanted aesthetic without any significant drawback in terms of responsiveness or preference, and it could be avoided to save time and no benefit would be missed in regards to those same terms. Future research will have to find if there are other advantages or disadvantages other than responsiveness or preference when utilizing a physically inspired model in this fashion, and future research could possibly find other areas where the use of such models would be beneficial, whether it be in different kinds of sound effects or in a different video game genre.

30 5 ACKNOWLEDGEMENTS A special thanks to Jon Allan for supervising the study and providing answers and ideas to my many questions throughout this process. Thanks to Emil Kerekes, Jakob Erlandsson, Olliver Andersson, Patrik Andersson, and Viktor Nilsson for providing comments and helping develop the study’s method, and a special thanks to Kerekes for opposing the thesis. Thank you!

31 6 REFERENCES Cockos. (2020). Reaper 6 (Version 6.0.3). Cockoc Inc. https://www.reaper.fm/ Dennaton Games. (2012). Hotline Miami. Austin, TX: Devolver Digital. Dobashi, Y., Yamamoto, T., Nishita, T. (2003). Real-time rendering of aerodynamic sound using sound textures based on computational fluid dynamics. ACM Transactions on Graphics, 22(3), 732-740. https://doi.org/10.1145/882262.882339 Epic Games. (2020). Epic games launcher (Version 10.15.5). Epic Games Inc. https://www.epicgames.com/ Epic Games. (2015). Infinity blade: adversaries (Unknown version) Epic Games Inc. https://www.unrealengine.com/marketplace/en-US/product/infinity-blade-enemies Epic Games. (2018). Soul: cave (Unknown version). Epic Games Inc. https://www.unrealengine.com/marketplace/en-US/product/soul-cave Epic Games. (2020). Unreal engine 4 (Version 4.24.2). Epic Games Inc. https://www.unrealengine.com/en-US/ Infuse Studio. (2019). Medieval dungeon (Unknown version). Epic Games Inc. https://www.unrealengine.com/marketplace/en- US/product/a5b6a73fea5340bda9b8ac33d877c9e2 Jacobsen, B. (2018, May 16). How to maintain immersion (+ reduce repetition & listening fatigue) in game audio:. A Sound Effect. https://www.asoundeffect.com/game-audio- immersion/ Kain, E. (2019, December 31). The best – and most important – video games of the decade. Forbes. https://www.forbes.com/sites/erikkain/2020/12/31/the-best---and-most-important--- video-games-of-the-decade-20102019/#250ea6dd7c84 Kypreos, E. (2018, July 26). Xbox one vs xbox 360 – is it time to upgrade?. Trusted Reviews. https://www.trustedreviews.com/opinion/xbox-one-vs-360-2899789 Loveridge, S. (2019, February 28). Sony ps4 vs ps3. Trusted Reviews. https://www.trustedreviews.com/opinion/sony-ps4-vs-ps3-2914323 Nvidia. (2020). Shadowplay (Version 3.20.3.63). https://www.nvidia.com/sv- se/geforce/geforce-experience/shadowplay/ Phillips, W. (2014). A composer’s guide to game music. MIT Press. Prop Garden LLC. (2018). Free fantasy weapon sample pack (Unknown version). Epic Games Inc. https://www.unrealengine.com/marketplace/en- US/product/e4494c76c3b348aba7ef9b263a6dd496 Stockselius, C. (2018). Repetitiv ljuddesign och dess inverkan på spelare [Repetitive sound design and its impact on players] [Bachelor’s thesis] University of Skövde. DiVA. http://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Ahis%3Adiva-15389

32 Student’s t critical value. (n.d.). Richland Community College. Retrieved March 31, 2020, from: https://people.richland.edu/james/lecture/m170/tbl-t.html Rockstar Games. (2013). Grand theft auto v. New York: Rockstar Games. Team Cherry. (2017). Hollow knight. Adelaide: Team Cherry. Thatgamecompany. (2012). Journey. Tokyo: Sony Interactive Entertainment. Toftedahl, M. (2019, September 30). Which are the most commonly used Game Engines?. Gamasutra. https://www.gamasutra.com/blogs/MarcusToftedahl/20190930/350830/Which_are_the_most_ commonly_used_Game_Engines.php Vachon, J-F. (2009, February). Avoiding tedium: fighting repetition in game audio [Paper Presentation]. AES 35th International Conference, London, UK. http://www.aes.org/e- lib/browse.cfm?elib=15158 Verron, C., Drettakis, G. (2012, October). Procedural audio modeling for particle-based environmental effects [Paper Presentation]. AES 133rd Convention, San Francisco, USA. http://www.aes.org/e-lib/browse.cfm?elib=16506 West, M. (2008, July 16). Measuring responsiveness in video games. Gamasutra. https://www.gamasutra.com/view/feature/132122/measuring_responsiveness_in_video_.php

33 APPENDIX A Below are pictures of Form A. Form B is identical.

Figure 13. Picture of the first page and first four questions on the form.

For the first question the options are: Equally responsive/No Difference, More Responsive (Test 1 or Test 2), and Much More Responsive (Test 1 or Test 2). For the third question the options are: Equally responsive/No Difference, Preferred More (Test 1 or Test 2), and Preferred Much More (Test 1 or Test 2).

Figure 14. Picture of the first part of the second page of the form. Included are the first four questions.

Figure 15. Picture of the second part of the second page of the form. Included are the three questions following figure 11.

36 table 16. Picture of the last part of the second page of the form. Included are the final two questions which are used to get participants’ views on the experiment’s ecological validity.

37 APPENDIX B Table of ratings and motivations to answers. A and B are categories for whether test 1 or test 2 is variational (A = Test 2 variational, B = Test 1 variational). Ratings have been reversed for the B-version to follow the ratings of the A-version.

Table 12. Table of all unabridged and untranslated answers to the responsiveness and preference questions from the form. If possible, please describe the If you preferred one of the tests. Please Test RATING - difference you noticed and how it RATING - describe what affected this decision and Subject Timestamp RESPONSIVE affected the game's responsiveness. PREFERENCE why it made you prefer either test more. 3/17/2020 A-1 13:14:53 0 0 The second Test had a better responsiveness when dealing more damage while moving the mouse. The 3/17/2020 In terms of Damage and strike Zombies didn't get stuck on the sword A-2 13:33:53 1 response while moving mouse. 1 either as they did sometimes in Test 1. I perceived that the audio was more delayed in test 1. I also think the audio 3/17/2020 in test 2 was brighter and/or higher in Test 2 felt more responsive than test 1 A-3 13:54:33 1 volume. 1 but not bu a lot. the attack sounds were faster and it felt like a more polished experience 3/17/2020 therefor the attack felt faster and more and I also liked the faster pacing that it A-4 15:49:43 2 responsive 1 felt like the sound/attack enabled 3/17/2020 I'd like a dungeon crawler with this 0 A-5 16:04:28 0 graphics and sound! Mer rörelse i i hur man rörde sig. 3/17/2020 Snabbare response när man A-6 16:19:48 -1 attackerade motståndanre. 0 Test two might have been "brighter"? It felt faster and more engaging. But it The gameplay in the second test felt also depends on the mood you have 3/19/2020 faster. More minions and sharper when you play. The dungeon might A-7 14:03:46 1 sounds 1 benefit from the settings in test 1. Test 2 felt more dynamic with the different slicing sound effects and it was more enjoyable. Test 1 felt monotone in 3/19/2020 regards to the sound effects being very A-8 15:19:35 0 1 similar to each other sound from hitting enemies was much 3/20/2020 faster, test 1 was hitting sound after A-9 17:41:39 2 animation 0 was the same for me 3/21/2020 0 A-10 15:38:51 0 ljuden ändrades när man träffade Jag gillade test 2 mer för att det kändes motståndare i test 2. I test 1 lät det lika mer verklighetstroget att det inte låter dant varje gång. Det kändes lite mer exakt lika dant varje gång man slår. Men verklighetstroget att ljudet ändrades. däremot gillade jag originalljudet i test 1 (vet inte om det är för att man träffade mer än test 2, det var mindre 3/23/2020 olika delar på motståndaren eller om högfrekvent. Men jag föredrog ändå test A-11 22:56:50 1 det var random?) 1 2 lite mer. 3/24/2020 I felt a slight delay on the first test. The responsiveness made it more feel A-12 13:13:19 1 Attacks were made later, I feel. 1 like I was immersed in the game/action. 3/17/2020 B-13 14:48:22 0 0 Test 1 was easier to understand when I got 40 points and when I got 10 points. In test 1 I thought about the surround of the fire on the walls. It may have been 3/17/2020 the same in test 2 but I did not think B-14 15:20:27 0 1 about it then. Båda gångerna lät det lika bara att den andra hade fler fienden, därmed Båda var lika som sagt innan var det 3/17/2020 var audion från ex slagen mot bara test 1 som hade kortare tid för B-15 16:05:49 0 fiendena mera frekventa 0 spawns. Så ingen åsikt The test 1 felt odd in a way for me, the sounds were more chaotic in a way but I got used to it. And on test 2 it felt 3/17/2020 smoother. But I thought that it was My preferred test is going to be the 2nd B-16 17:04:46 -2 due to that I got used to the game. -1 one. Because it was simpler to follow Test 2 kändes mer "rätt" och ljudet när Ingen skillnad som jag märkte. man slogs var "köttigare" i brist på bättre Däremot kändes test 2 mer "rätt" när ord och bar en större effekt på helheten man spelade men jag vet inte om det och var behagligare för örat. Test 1 lät var på grund av responsiviteten. Det högre (alltså ljusare) vilket efter flertalet 3/17/2020 kan bero på andra faktorer som jag slag blev lite skärande nästan. Högst B-17 21:02:44 0 märkte istället. -2 personlig åsikt då jag lider av tinnitus. 3/18/2020 Did not know there was any difference B-18 15:42:08 0 between the two. 0 3/18/2020 B-19 17:51:19 0 I did notice any differences 0

38 3/19/2020 I dont know if i noticed any difference B-20 13:44:41 0 really. 0 I felt as if test 2 had more of a "surround" feeling. Not sure if it's me just imagining stuff but I felt more enveloped in the room of test 2. The footsteps of the "goblins" felt as if they were behind me when I wasn't looking at them in test 2. Again, this is something that I just payed attention to in test 2 so not sure, it might've been like that in test 1 as well.

Test 2 also felt more satisfying while hitting these goblins, it felt more responsive. Whenever I hit the goblins in test 1 it felt clumsy, but in test 2 it felt more "realistic", in a way.

My own footsteps wasn't something As mentioned above I felt as if test 2 was that I payed attention to in test 1 but in more enveloping and a little bit more test 2 I reacted to an unnatural sound responsive in what I did. Though this whenever I was jumping around. could be just me getting used to the There were no sounds of me landing, game and the room, it was hard to tell. not sure if that was there in test 1 but There weren't any enormous differences 3/19/2020 I did notice it quite clearly that it wasn't that I could hear or experience, more of B-21 14:25:48 -2 there in test 2. -1 a subconscious experience I think. Som jag sa innan så tyckte jag att slagen Jag tyckte att ljudet av slagen var mer lät mindre blöta när en slogs, vilken 3/19/2020 blöta och inte lika snabba i första kändes mindre realistiskt än första B-22 15:44:37 1 testet. 1 delen. 3/20/2020 The sound of landing after a jump was B-23 16:26:19 0 a bit delayed in both tests. 0 3/27/2020 Mer variation i ljuden när man slog Mer variation i ljuden ger större B-24 16:41:45 -1 fienderna i Test 2. -1 inlevelse.