BACHELOR THESIS
“How does Sound Design Impact the Players Perception of the Level of Difficulty in a First Person Shooter
Game?”
Sebastian Darth 2015
Bachelor of Arts Audio Engineering
Luleå University of Technology
Department of Arts, Communication and Education
“How does sound design impact the players perception of the level of difficulty in a first person shooter game?”
Sebastian Darth 2015
Bachelor of Science Audio Engineering Luleå University of Technology
Department of Arts, Communication and Education
Abstract
This research paper explore if a games sound design have an impact on a games perceived difficulty from a players point of view. The game industry produces many game titles that are similar in terms of mechanics and controls, for example, first person shooter games. This thesis investigates if the differences in sound design matter. Where many first person shooter games are very similar in terms of gameplay, controls and sound design, these sound designs are similar though not identical. With new information on how players use sound when they play games, interesting new games styles, mechanics and kinds of game-play could be explored. This study found that players use the sounds of his or her allies in the game more than any other sound when presented different tasks in games. It was also shown that players use the sound of weapon fire to know where their targets are and when they need to take cover to avoid defeat. Finally it was suggested that loud weapons might impact the perceived difficulty as it might cover the sounds of the various voices.
Acknowledgments
I would like to thank my supervisors Nyssim Lefford and Jan Berg for the help and input during the construction of this research, I would also like to thank the members of the research committee and the persons who took their precious time to participate in the active playing test.
1. Introduction ... 5
1.1 Background ... 5
1.2 Purpose ... 6
2. Method ... 7
2.1 The Games ... 7
2.2 Pre-study ... 8
2.3 The Sounds ... 9
2.4 Choosing segments of the game to analyse ... 11
2.5 Analysing the sound design of the three comparable games ... 12
2.6 Analysing the VO sounds ... 12
2.7 Analysing the Weapon sounds ... 15
2.8 Active playing test ... 18
2.9 The questionnaire ... 19
3. Results ... 20
3.1 Analysis of the sounds mentioned by the test subjects ... 20
3.2 Distribution of answers from the questionnaire ... 20
3.3 Distribution of answers from the questionnaire in the VO category ... 22
3.4 Distribution of answers from the questionnaire in the weapon category ... 23
3.5 Results from the second part of the questionnaire ... 24
4. Analysing the data from the active playing test ... 25
4.1 Analysis of the level of difficulty responses ... 25
5. Discussing the data from the active playing test ... 27
6. Critique ... 27
7. Future work ... 28
8. Conclusion ... 28
9 References ... 29
9.1 Data points ... 29
9.2 Software ... 30
10. Appendix ... 31
10.1 Appendix 1 answer form for the pre-study ... 31
10.2 Appendix 2 Comparison Calculation ... 32
10.3 Active playing test questionnaire ... 33
10.4 appendix 4 test subjects answers from the active playing test ... 36
10.4.1 answers from Battlefield: Bad Company 2 ... 36
10.4.2 answers from Call of Duty: Black Ops ... 39
10.4.3 answers from Battlefield 3 ... 42
1. Introduction
A first person shooter game (FPS) is game with projectile-based combat game with a first person perspective, that is that the player sees the game world through the eyes of the games protagonist. In a first person shooter game the field of view is limited to circa 85 degrees, this leaves 275 degrees of vision that are unable to give the player visual information. In addition a player cannot see enemies or objectives that are blocked from their vision by obstacles in the game. In order give the player information from those critical areas another communication medium is required. A suitable medium for carrying this information is sound as it can give cues to the player without requiring that the source of the sound is in the player’s line of sight. The purpose of this study is to research if different sound designs can influence the playability of a game with and if these sound designs choices impact the perceived difficulty.
1.1 Background
The field of game sound has its roots in film and cinema sound and a lot of the research done in game sound originates from film and cinema. It is not until recently that the area of game sound became regarded as a specialized field of research and the differences between game sound and traditional linear media like film or cinema was explored.
Karren Collins (2013) states that the interactive sounds in a video game are kinesonically syncretic, meaning that that sounds are fused to actions as opposed to being fused to images.
Interactive sound is explained as the sounds that are initiated by the game or the player. These sound are the primary differences between the linear media and games.
Sound design is the process of recording, selecting, mixing and processing the sounds for a film, game or other medium that involves sound. In traditional media like cinema and theatre and other linear media the sound design is not influenced by the audience, the sound design is the same without any regard for the audience.
Film and cinema does not use interactive sounds. Games are not linear and the player of the game can make decisions that influence the sound design and the sound design can influence the player to take actions that has an impact on the world the game takes place in.
Some games are perceived as more difficult than others and the sound design could be one of the factors that contribute to a games perceived difficulty. Since a player interacts with the information they are given and sound is an information carrier, it could be argued that sound influence how players interact with sound and therefore how difficult the players perceive the games. Bruce Walker and Jeffrey Lindsay (2006) found that navigating an invisible maze using only sounds as navigation cues, different sounds where shown to be more or less successful in aiding the test subjects to complete the task. A game can be seen as many different tasks that needs to be completed in order to progress in the game. Sound has an impact on the flow shown by Simon Lindskog (2013) and immersion as shown by Laura Ermi and Frans Mäyrä (2005). Simon Lindskog (2013) summaries Csikszentmihalyis term flow as:
“when a person experience control, enjoyment and a sense of achievement in an activity”.
Laura Ermi and Frans Mäyrä define immersion as “becoming physically or virtually a part of the experience itself”. Thus, it is shown that sound has a big impact on flow and immersion and it could be argued that sound have a big impact on perceived difficulty.
Even though sound is shown to have an impact on the game the author have noticed a trend among gamers to mute the game sound in favour for music from another source or silence.
There is an entire forum thread at the PlayStation Universe online forum dedicated to find games that is playable without sound. A similar forum thread was found on the www.giantbomb.com forums.
Does that mean that the sound in a game is not critical to success, or is the performance of the
1.2 Purpose
The purpose of this study is to find out if and how different sound designs in a first person shooter (FPS) game impact the perceived level of difficulty. With this information a game developer can make more informed decisions regarding the sound design when creating a game. Ultimately further research could lead to the invention of exiting new ways to play games, with sound as a bigger part of the game mechanics.
The research presented here will address the question: does sound design influence the
player’s perception of difficulty in a first person shooter game?
2. Method
One pre-study and one active playing test where conducted to find out if the sound design of a game could influence a players perceived difficulty of the game. The first part involved analysing the sound designs of three similar commercially produced FPS games and determining which of the sounds the players thought were most important for gameplay. In the second part, the games analysed are evaluated for players perceived level of difficulty.
First, there was a pre-study in which a committee of players experienced with games and sound engineering helped identify the three most similar games, and assessed which sounds in these games were most important for game play. In the first part of the study, the sound designs in these games were analysed individually and then compared. Finally, a last test was designed to find out how a group of test subjects acted and interacted with the sounds and how difficult they perceived the different games. The later test was designed to find out how players not in this committee perceived the difficulty of these games and how the players utilized the sounds to complete the different tasks presented by the game.
2.1 The Games
The games chosen for the test where chosen from a small selection available at the university and the authors small collection of games. Only first person shooter games with focus on combat with firearms were picked. Only high budget AAA games where used for the test to make sure that all the games where representative of a commercial FPS game.
The following games made the first cut: Bulletstorm (EA,2011), Payday 2(505 Games, 2013), Crysis 3(EA, 2013), Call of Duty: Black Ops(Activision, 2010), Battlefield 3(EA, 2011) and Battlefield: Bad Company 2(EA, 2010). In each of these games, a specific level was selected for use in the pre-study and experiment, the level used are listed in table: 1, all the levels where the first playable level after the tutorial level and the chosen level of difficulty for all games was the “normal” difficulty.
Table: 1. List of levels used.
Game Level
Battlefield: Bad Company 2 Cold War Call of Duty: Black Ops Operation 40
Battlefield 3 Operation Swordbreaker
Bulletstorm Chapter One: Just Like the Good Old Days
Crysis 3 Post Human
Payday 2 Jewellery store heist
These levels where chosen because they did not act as a level that taught the players how to use the controls or how to play an FPS game as the committee and the test subjects where expected to know that. The levels still introduced how the individual games mechanics worked to the players but still encouraged the players to solve the problems themselves.
The levels chosen by the committee to be most similar will briefly described below. All the
levels share the similarities that a small team accompanies the player and they progress
through a linear map to a certain objective. In Battlefield: Bad Company 2 the player progress
through a small village in a winter environment with the purpose to acquire a box loaded to a
truck at the far end of the village. In Call of Duty: Black Ops 2 the player begins by fighting
his/her way through a street in a major city to acquire a car, after that he/she attacks an enemy
stronghold with the purpose to assassinate Fidel Castro.
Both scenarios are set in Cuba the year 1961. In Battlefield 3 the player progresses through a Middle Eastern city where he/she is attacked by enemies.
2.2 Pre-study
In the first experiment a small research committee consisting of four members experienced in sound engineering and gaming was formed. Two of the players where experienced with the games that where used in the pre study and two where inexperienced with the games used in the pre study. Their purpose was to choose three games that had made the first cut that were similar enough in terms of gameplay and the basic level of challenge to discard their differences in gameplay and controller layout. Each member of the committee played each of the game for ten minutes each to make sure that the foundation of the comparison was the same for all of the games. One game served as a reference-game against which the other games were evaluated. The game that was chosen as a reference game was Battlefield: Bad Company 2 as it was the game with the highest Metacritic (Metacritic, 2015) score as shown by table: 2 Metacritic is a website that distils the reviews of some carefully chosen critics to capture the essence of critical opinion. The reference game was the game out of the six available games with the highest Metacritic score as the game with highest Metacritic score can be considered the objectively best game.
Table: 2. The games used in the pre-study ranked highest to lowest Metacritic score taken the fourth of march 2015, the number of individual reviews the score is based on is also included.
# Game Metacritic score Number of reviews
1 Battlefield: Bad Company 2 88 75
2 Call of Duty: Black Ops 87 89
3 Battlefield 3 84 57
4 Bulletstorm 84 83
5 Crysis 3 76 45
6 Payday 2 75 18
After every level was played the members of the committee answered a short questionnaire in which the members of the committee was asked to compare each game to the reference game.
The questions were “how similar are the controls?” “Is the difficulty comparable?” and “Are the tasks comparable?”. The question “Is the difficulty comparable?” was rated on a different scale where 5 was no difference in difficulty and 1 or 10 was big difference in difficulty. The questionnaire was written in English as all the games were in English, the members of the committee could answer the question in both English or Swedish depending on what they language they found most effective to communicate their thoughts. The answers were later translated to English by the author. For the actual questionnaire see appendix 1.
Each question was answered with a number between one and ten on a scale where a score of
one being very different and a score of ten very similar. The results from those questions
where then added up for each game to get a total score that describe the comparability to the
reference game. The games most comparable to the reference game were shown to be
Battlefield 3 and Call of Duty: Black Ops as shown by table: 3.
Table: 3. Comparability score with the two games used together with the reference game in the analysis marked with green text, the comparability score calculation is explained in appendix: 2.
To control how much experience each member of the committee answered a question on how much experience they had with the different games. This was to investigate if a player with much experience with a game had different preferences than a player with less experience.
When analysing the data from the experience question it was found that two of the players scored higher on this question than the two other and could therefor be considered more experienced. For the reference game only the question regarding the member of the committees experience was asked, as a game cannot be compared with itself.
The committee did the test using Yamaha HS 80 monitors on a Microsoft Xbox 360 game system. The visual monitor used was a 47-inch LED TV, the pre-study was preformed in a home environment, the committee was allowed to set the volume to his or her own liking. The experiment leader was present at the location for the experiment to be able to answer any questions and observe the playing of the committee. The playing order of the six games was randomised for each member of the committee to avoid systematic error.
In addition to confirming the comparability of the games, the committee was asked to list the sounds they found most important to the gameplay in each game, In addition to confirming the comparability of the games, the committee was asked to list up to ten sounds from each game that they found most important for the gameplay.
The purpose of asking what sounds they considered most important was to select what sounds that the analysis was going to focus on.
2.3 The Sounds
To find what sounds to focus on in the analysis the members of the committee where asked to list up to ten of the sounds they found most important for each game. Each member's answers were then analysed to see if a pattern could be found. Their answers were then analysed and each of their sounds put into a category, the categories where designed so that each sound had a category to fit in. The categories were created after the subjects’ responses were collected.
The categories were voice over (VO) sounds, where all sounds connected to voice were placed. Weapon sounds, where the sounds of weapons was placed, both sounds generated by players’ actions and artificial intelligences (AI) actions. Explosion sounds, where all sounds of exploding grenades and other explosions was placed. Foley sounds, where all the Other (non-explosion) foley sounds sound was placed, such as footsteps and vehicles. Music, where all music sounds was placed. Atmosphere sounds, where all atmosphere and ambience sounds where placed, like sounds of the wind and functions sounds, where sounds clearly designed to alert the player that something is happening or is going to happen was placed, such as the health of the player is dangerously low or the players objective has changed. The sounds that where most common where the VO sounds and the weapon sounds as shown by fig 1 only the
# Game Comparability score
1 Battlefield 3 79
2 Call of Duty black ops 2 66
3 Crysis 3 55
4 Bulletstorm 51
5 Payday 2 43
Fig: 1. Distribution of answers from the pre-study
It could then be seen if some categories were more common than others (VO sounds and weapon sounds.) By asking the members of the committee to rank their experience between one and ten and combining that number from all the six games it could seen how experienced the members were with the six games. As show by fig: 2 experienced players mentioned the VO sounds more than the inexperienced players, and the inexperienced players mentioned weapon sounds more than the experienced players. No further analysis of the committees experience was made.
0 5 10 15 20 25 30
N u m b er o f M en ti on s
Sound categories
Distribution of answers from the pre-‐study
Fig: 2 Distribution of answers from the pre-study between experienced and inexperienced players.
2.4 Choosing segments of the game to analyse
The levels chosen for analysis were the same ones that where played by the members of the committee in the pre-study. By observing how far the committee progressed in the games during their ten-minute playtime in each game, the checkpoint in each game could be set so that the checkpoints could be considered comparable through all the three games.
It was found that all players had reached the approximate same checkpoint when their time ran out. Only the checkpoints for the three games chosen for further analysis will be explained as they are the only ones that where considered for this test. In Battlefield: Bad Company Two it was found that after ten minutes had passed most of the members in the committee had played up to or to just after the player is asked to tag an enemy tank so that it could be destroyed by aircraft allied to the player. In Call of Duty: Black Ops it was found that after ten minutes had passed most members of the committee had played up to the part where the Fidel Castro lookalike was shot and killed by the player in a slow motion event. In Battlefield 3 it was found that after ten minutes had passed most members of the committee had played up to the part when the player fires an RPG against an enemy sniper located in a hotel in a slow motion event. All three checkpoints took the members of the committee circa ten minutes to reach and all three checkpoints are triggered by the player killing or destroying an object with a game-mechanic that is not presented earlier in the game.
Those checkpoints where used to mark the endpoint of the analysis and later they would act as the endpoint for the subjects in the active playing test.
All three checkpoints took the members of the committee circa ten minutes to reach and all three checkpoints are triggered by the player killing or destroying an object with a game mechanic that is not presented earlier in the game. To acquire the sounds to analyse a play- through of each game from the start to the designated checkpoint in each game was recorded from the Xbox 360 to a computer with the digital audio workstation Pro Tools 11 installed.
The sound options was set to default for all three game except for the sound system option that was set to “TV” as it was the option that fitted the sound distribution system that was used for the analysis best.
0 5 10 15 20
N u m b er o f m en ti on s
Sound categories
Distribution of answers from the pre-‐study between experienced and inexperienced
players.
Experienced players
Inexperienced players
2.5 Analysing the sound design of the three comparable games
To analyse the sound design each game was recorded from the start until the same checkpoint as in the experiment, the reasoning for not using a fixed time when recording was that then the skill of the player would significantly influence the results, by choosing to play and record the same length as the experiment the comparability between the games where preserved.
This yielded three stereo audio-files that could be analysed. Then the sound designs of three segments will be analysed. The analysis is limited to the categories of sounds the committee determined were most important for game play, the VO sounds and the weapon sounds. Both the nature of the sounds and the frequency they occur will be considered.
2.6 Analysing the VO sounds
The VO sounds were split into four different sub-categories, story sounds where dialogue that took the narrative further where placed, instruction sounds where dialogue that instructed player on how to solve different problems where placed. Enemy VO where the different voices and shouts of the opponents where placed. Gameplay sounds where sounds generated by the gameplay was placed, for example when someone yells ”grenade!” when a grenade is thrown in the game or the “get over here” when the player goes the wrong direction.
The VO sounds in the recorded play throughs were than analysed and for each category the total amount of time each category was represented and how many times each category was represented. This was to measure how many seconds and how many times each category was represented in the games.
These following bar charts show how many seconds the story and instruction VO sub- categories are represented in each games analysed checkpoint.
Fig: 3. Bar-chart showing the total running time of the story sub-category in seconds.
132
116
97
T ime in s ec on d s
Games
Running time of Story Instances
Battlefield: Bad Company 2 Call of Duty: Black Ops Battlefield 3
Fig: 4. Bar-chart showing the total running time of the instruction sub-category in seconds.
These following bar charts show how many times each VO sub-category occurred in each of the games analysed checkpoint
Fig: 5. Bar-chart showing the total number of occurrences of the story sub-category.
21
47
22
T ime in s ec on d s
Games
Running time of Instruction Instances
BattleGield: Bad Company 2 Call of Duty: Black Ops BattleGield 3
13
6
10
St or y in st an ce s
Games
Number of Story Instances
BattleGield: Bad Company 2 Call of Duty: Black Ops BattleGield 3
Fig: 6. Bar-chart showing the total number of occurrences of the instruction sub-category
Fig: 7. Bar-chart showing the total number of occurrences of the gameplay sub-category
91
9
35
In st ru ct io n in st an ce s
Games
Number of Instruction Instances
BattleGield: Bad Company 2 Call of Duty: Black Ops BattleGield 3
19
45
34
G am ep la y in st an ce s
Games
Number of Gameplay Instances
BattleGield: Bad Company 2 Call of Duty: Black Ops BattleGield 3
Fig: 8 Bar-chart showing the total number of occurrences of the enemy VO sub-category
2.7 Analysing the Weapon sounds
The weapon sounds where divided into two parts, level and spectrum. The level in dB where compared between the players weapon and the weapons of the AI where compared.
Only the players weapon and the weapon of the AIs spectral content were compared. Because the quantity of weapon sounds depends heavily on the skill and play style of the player it was not considered for further analysis. The audio for the spectrograms and levels gathered by recording the sound from the Xbox 360 to a Pro Tools 11 session, for each game a spectrogram was taken when only the players weapon was firing and when only the players allies was firing. The spectrogram was made with the Bluecat FreqAnalyst plugin. The levels was measured with the HOFA 4U meter fader and ms pan plugin.
These following pictures are print screens from the Bluecat FreqAnalyst plugin. On the X- axis frequency in Hz between 10 Hz and 22k Hz is displayed, on the Y-axis level in dBFS is displayed.
30
11
33
En em y V O in st an ce s
Games
Number of Enemy VO Instances
BattleGield: Bad Company 2 Call of Duty: Black Ops BattleGield 3
Fig: 9. Spectral analysis of the players weapon in Battlefield: Bad Company 2.
Fig: 10. Spectral analysis of the players weapon in Call of Duty: Black Ops.
Fig: 11. Spectral analysis of the players weapon in Battlefield 3.
Fig: 12. Spectral analysis of the AIs weapon in Battlefield: Bad Company 2.
Fig: 13. Spectral analysis of the AIs weapon in Call of Duty: Black Ops.
Fig: 14. Spectral analysis of the AIs weapon in Battlefield 3
The following table shows the level in negative dB of the weapon sounds in all of the three games.
With this understanding of the games’ sound design set as a foundation, a active playing experiment was conducted in which subjects not on the committee were asked to play these same levels and evaluate their level of difficulty. There were also asked how much the sound helped them. The results of this experiment are discussed in light of the analysis of the sound designs.
Fig: 15. Bar-chart displaying level of weapon-fire.
2.8 Active playing test
The active playing test took place in Luleå University of Technology’s facilities in Piteå where a group of twelve test subjects with an interest in gaming, played three games and answered a questionnaire that consisted of two parts. The order of the games where randomized for each test subject. The test subjects where students at the university with the only common ground being their interest in gaming. To make sure that the subjects for the test had enough experience to complete the games only people that considered themselves gamers or had gaming as a hobby were allowed to take part in the study. Those people could be considered to understand how game mechanics works and could then figure out how to play the games even though they never played them before. Because the supply of people that consider themself gamers is limited at the facility where the experiment took place, the experiment could not disregard all subjects that lacked experience in the FPS genre.
The subjects did not have any time limitation and they could restart the game many time they needed to complete the game as the performance of the subjects where not consider in this
-‐10 -‐8 -‐6 -‐9 -‐7 -‐5 -‐4 -‐3 -‐2 -‐1 0
Player AI Player AI Player AI
BattleGield: Bad Comapny 2 Call of Duty: Black Ops BattleGield 3 dBFS
GAMES
Level of Weapon Fireing
The experiment was performed in a small acoustically treated room on a forty-two inch LED television. The gaming station used was a Microsoft Xbox 360. The sound distribution system used was the TVs 3,5 mm tele-output and a pair of Beyer dynamics DT 770 studio headphones. The headphones where used because the room where not sound isolated and that led to noise leaking in to the room from outside sources potentially disturbing the subjects as they played the games. To compensate for the use of headphones the output option for the sound in each game were set to “headphones”. The subjects were instructed to play the games to the same checkpoints as in the analysis and then answer the first part of the questionnaire after each checkpoint was reached. After all three games were played to their respective checkpoint they where instructed to answer the second part of the questionnaire.
The subjects could contact the leader of the experiment at any time during the time they played the games.
2.9 The questionnaire
The questionnaire consisted of two parts, in the first part the subjects where instructed to play each game to a designated checkpoint in each game that was predetermined and chosen to be comparable between the three games, the checkpoints where assumed to take these players about 10 minutes to reach, the same time as the committee as they where supposed to have the same background in playing videogames as the committee.
In the first part of the questionnaire the subjects where asked to “List up to five actions/interactions that you performed that were influenced by sound.”. And “For each action/interaction, briefly describe how sound aided you.” The first part was repeated after each game was played.
In the second part of the questionnaire the subjects where asked to rate how difficult they perceived the game and how much they experienced that the sound aided them in performing the various tasks in the game. The rating was made with a one to five scale where one was very easy/no aid and five where very hard/much aid.
The second part was designed to show if the subject experienced a difference in difficulty between the games The subjects answered the second part of the questionnaire after playing all the three levels to force the subjects into compare the games against each other. The questionnaire did not specifically ask for the sounds that were analysed (VO sounds and weapon sounds) as that could have an impact on how the subjects played the games and therefore have an impact on the results. However, this will be matched against the analysis performed above in the discussion section.
3. Results
3.1 Analysis of the sounds mentioned by the test subjects
The data was coded and categorized using the same categories as the pre-study (VO sounds, Weapon sounds, explosion sound, foley sounds, music, atmosphere sounds and functions sounds). An additional category (cinematic sounds) was added to fit sounds that were connected to cut scenes and other cinematic events. The top two most represented categories (VO sounds and weapon sounds), where divided into sub-categories with the purpose to show how the subjects used the sound. The sub-categories in the VO category were instructions where the same as in the first analysis. (Story sounds, Instruction sounds, Enemy VO, Gameplay sounds)
The sub-categories in the Weapon category were: localisation, where examples of the subjects using the sounds of weapons to localize both enemy and friendly AI. Cover, where examples of the subjects using the sound of weapons to identify that they needed to take cover was placed. Gameplay where examples of the of the subjects using the sound of weapons to make gameplay decisions such as reload their weapon or what weapon to use.
3.2 Distribution of answers from the questionnaire
The following pie charts show how the test subjects answered on the questions “list up to five actions/interactions that you performed that was influenced by sound.” and “For each action/interaction, briefly describe how the sound aided you.”. The categories used for categorisation was the same that where used in the analysis of the data from the pre-study.
(VO sounds, Weapon sounds, explosion sounds, foley sounds, music, atmosphere sounds,
function sounds)
Fig: 16. Distribution of answers Battlefield: Bad Company 2.
Fig: 17. Distribution of answers Call of Duty: Black Ops.
Fig: 18. Distribution of answers Battlefield 3.
VO Sounds 38%
Weapon Sounds 30%
Function Sounds 19%
Foley Sounds 2%
Explosion Sounds 8%
Music 3%
Other 14%
Distribution of answers: BattleIield: Bad Company 2
VO Sounds 56%
Weapon Sounds 14%
Function Sounds 14%
Foley Sounds 3%
Explosion Sounds 5%
Music 3%
Cinematic 5%
Other 16%
Distribution of answers: Call of Duty: Black Ops
VO Sounds 51%
Weapon Sounds
27% Function Sounds
16%
Explosion Sounds 3%
Foley sounds 3%
Other 6%
Distribution of answers: BattleIield 3
3.3 Distribution of answers from the questionnaire in the VO category
These following pie charts are showing the distribution of the test subjects answers sorted into the sub-categories in the VO category (Story sounds, Instruction sounds, Enemy VO, Gameplay sounds) Each pie chart is representing a game. It was found that the story sounds sub-category where not mentioned by the test subjects and is therefor not represented in the results.
Fig: 19. Distribution of answers in the VO category: Battlefield Bad company 2.
Fig: 20. Distribution of answers in the VO category: Call of Duty Black Ops.
Fig: 21. Distribution of answers in the VO category: Battlefield 3.
Instructions 69%
Enemy VO 16%
Gameplay 15%
Distribution of answers in the VO category: BattleIield Bad company 2
Instructions 42%
Enemy VO 21%
Gameplay 37%
Distribution of answers in the VO category: Call of Duty Black Ops
Instructions 88%
Enemy VO 6%
Gameplay 6%
Distribution of answers in the VO category: BattleIield
3
3.4 Distribution of answers from the questionnaire in the weapon category
These following pie charts are showing the distribution of the test subjects answers sorted into the sub-categories in the weapon category (Localisation, cover, gameplay). Each pie chart represents a game.
Fig: 22. Distribution of answers in the weapon category: Battlefield Bad company 2.
Fig: 23. Distribution of answers in the weapon category: Call of Duty: Black Ops.
Fig: 24. Distribution of answers in the weapon category: Battlefield 3.
Cover 40%
Localization 50%
Gameplay 10%
Distribution of answers in the weapon category:
BattleIield Bad company 2
Cover 14%
Localization 57%
Gameplay 29%
Distribution of answers in the weapon category: Call of Duty: Black Ops
Cover 40%
Localization 60%
Distribution of answers in the weapon category:
BattleIield 3
3.5 Results from the second part of the questionnaire Raw data extracted from the second part of the questionnaire.
table: 4. Answers from the test subjects on the question “How difficult did you perceive the game?”
“How difficult did you perceive the game?”
Subject #
Battlefield: Bad Company 2
Call of Duty:
Black Ops Battlefield 3
1 1 1 1
2 5 2 4
3 4 3 3
4 2 1 2
5 4 3 3
6 2 4 2
7 4 3 4
8 2 1 3
9 4 3 1
10 3 2 3
11 3 2 4
12 4 2 3
MEAN 3,17 2,25 2,27
table: 5. answers from the question “How much did you perceive that the sound helped you perform the different tasks in the game?”
“How much did you perceive that the sound helped you perform the different tasks in the game?”
Subject #
Battlefield: Bad Company 2
Call of Duty:
Black Ops Battlefield 3
1 4 3 4
2 4 2 3
3 5 4 4
4 2 2 3
5 3 4 4
6 2 3 1
7 3 2 2
8 2 1 3
9 3 4 3
10 3 3 4
11 2 4 4
12 3 4 3
MEAN 3 3 3,17
4. Analysing the data from the active playing test
The analysis begins with analysing the second part of the questionnaire and then the results from the first part will be analysed in the light of the second part.
4.1 Analysis of the level of difficulty responses
The answers from the second part of the questionnaire was analysed with a two-tailed t-test, first Battlefield: Bad Company 2 was tested against Call of Duty: Black Ops. Then Call of Duty: Black Ops as tested against Battlefield 3, and last Battlefield: Bad Company 2 was tested against Battlefield 3. The significant level is set to 0,05 and the degrees of freedom are 11, this gives a critical t-value of 2,201.
These following tables display the statistical analysis of the second part of the questionnaire.
The first table shows the outcome from the question “How difficult did you perceive the game?” the second table shows the outcome fro the question “How much did you perceive that the sound helped you perform the different tasks in the game?”
Table: 6. Statistical significance for the question “How difficult did you perceive the game?”
Game A Game B
Calculated t- value
Critical t- value
Statistically Significant Battlefield:
Bad Company 2
Call of Duty:
Black Ops 2,726857934 2,201 Yes Call of
Duty:
Black Ops Battlefield
3 1,253566341 2,201 No
Battlefield:
Bad Company 2
Battlefield
3 1,331988569 2,201 No
Table: 7. Statistical significance for the question “How much did you perceive that the sound helped you perform the different tasks in the game?”
Game A Game B Calculated t-
value Critical t-value Statistically Significant Battlefield:
Bad Company 2
Call of Duty:
Black Ops 0 2,201 No
Call of Duty:
Black Ops
Battlefield
3 0,51796977 2,201 No
Battlefield:
Bad Company 2
Battlefield
3 0,560611911 2,201 No
As shown by table: 4 there is no statistical significant difference in the test subjects perception of difference in difficulty between the games Battlefield: Bad Company 2 and Battlefield 3 nor between Call of Duty: Black Ops and Battlefield 3. Between the games Battlefield: Bad Company 2 and Call of Duty: Black Ops there is shown to be a statistical significance.
As shown by table: 5 there were no statistical significance between any of the games when the test subjects where asked, “How much did you perceive that the sound helped you perform the different tasks in the game?”
Because of the statistical significance in perceived difficulty between Battlefield: Bad Company 2 and Call of Duty: Black Ops the results are interesting, it was shown that Battlefield: Bad Company 2 was perceived as more difficult than Call of Duty: Black Ops.
The mean of the answers on the question “How difficult did you perceive the game?” for the games Battlefield: Bad Company 2 and Call of Duty: Black Ops is presented in table: 6, the table shows that Battlefield: Bad Company 2 has a higher mean value than Call of Duty:
Black Ops and can therefore be considered to have been perceived as more difficult by the
test subjects.
Table: 8. The mean of the answers on the question “How difficult did you perceive the game?”
Battlefield: Bad Company 2 3,17 Call of Duty: Black Ops 2,25
This might be caused by Call of Duty: Black Ops significantly higher amount of gameplay sounds in the VO category, this is supported by the answers from the test subjects that pointed out VO sounds as a sound they acted/interacted with a total of 56 % times (fig: 17). Compared to Battlefield: Bad Company 2 where the VO category only was mentioned 38 % (fig: 16) of the times, another difference is the distributions of the answers in the VO category, where Call of Duty: Black Ops displayed a gameplay that was 37 % and Battlefield: Bad Company 2 displayed a 15 % in the same category. This might suggest that the gameplay category has an impact on perceived difficulty.
By observing fig 16,17, 18 a pattern seems to be distinguishable, Battlefield: Bad Company 2 and Battlefield 3 the VO sounds is mentioned most, followed by weapon sounds and last function sounds. In Call of Duty: Black Ops the VO sounds where most mentioned followed by function sounds and weapon sounds that where mentioned the same amount of times. This follows the same pattern as in the pre-study where the different categories of sounds where mentioned in the same order. This suggests that the sounds most noticed by the test subjects and the committee where those that was linked to the VO.
As shown by fig: 19, fig: 20 and fig: 21 the most represented sub-category in the VO category was the information category, this suggests that many players rely on the spoken instructions in a game to solve different problems. This is backed up by the answers the subjects gave in the questionnaire; one of the test subjects wrote “The instructions from the leader of the group were essential to finish the mission.” Many others mentioned commands from the leader in the test subject’s team as instances that helped them in performing different tasks.
The story category was not mentioned at all by the test subjects as sounds that aided them in
any actions or interactions.
Fig 22, 23, 24 shows the distribution of answers in the weapon category, they show that the test subjects relied on the sounds of gunfire to localize enemies and knowing that they needed to get out of the way to survive in the game. In Call of Duty: Black Ops the test subjects mentioned gameplay sounds more than in the other two games. This is probably due to Call of Duty: Black Ops having a sound that encourage the player to reloading when the weapon they are using are running out of ammunition. This was noted by two test subjects and was only noticed in Call of Duty: Black Ops, and could possibly be an influence on the perceived difficulty.
When analysing the spectrograms (fig 9, 10, 11, 12, 13, 14) it shows that there is only a very small difference the players weapon and the AIs weapon in every game. It is shown that both Battlefield: Bad Company 2 and Battlefield 3 have a bump in the 100 Hz area boosting volume there by circa 10dB. It was also shown by fig: 25 that Call of Duty: Black Ops had a slight lower total volume than Battlefield: Bad Company 2 and Battlefield 3 (fig: 15) This was pointed out by one of the test subjects who wrote “The shoots was pretty weak in comparison with other games” and that that made in sound pretty unreal and childish.
The difference in weapon sounds could have an impact on perceived difficulty as a lower weapon sounds gives room for other sounds in the games sound design to give other information, such as VO sounds to give information to the players.
5. Discussing the data from the active playing test
According to this research the most important sounds in a game when it comes to perceived difficulty are the sounds linked to the VO, and the most important sounds in the VO category is sounds that are linked to the gameplay, such as friendly AI waring the player that a grenade is being used somewhere in the players proximity. This study also shows that players rely on the spoken instructions from the game to deal with various problems through the game.
It is suggested by the research that loud weapons might influence the perceived difficulty, possibly by making it harder to hear the various voice sounds coming from the players allies and enemies that are suggested to be more of value to the player.
It was shown that sounds linked the narrative and story was not relevant to the test subject’s perceived difficulty of the games.
This information might give a sound designer the information he or she need to make a game design that is supposed to encourage a specific style of gaming.
6. Critique
This research used both the objective analysis of the sound design in three games as well as the subjective input from both a committee and test subjects. This made it possible to link the test subjects comments to the data from the objective analysis, for example one test subject commented that the game Call of Duty: Black Ops weapon sound was “weak” in comparison to other games, this could be found in the objective analysis of the game as Call of Duty:
Black Ops as well as the game lacked an augmentation in the frequencies around one hundred
hertz that was found in the other games in this research giving it an less impressive weapon
sound. If either the measurement or the subjective answers where left out, the results would
As the games used in this were not designed by the author full control of the games could not be acquired, therefore the difference in other parts of the games designs apart from the sound design might have been the cause of the difference. To eliminate the chance of this a committee was formed and consulted when choosing the games used in this research.
However the limited pool of games available to the author and therefore the committee might have caused that the games used in this research where to different still to make accurate research.
7. Future work
Future work in this field may be to explore more in detail how the different categories influence the players’ perception of difficulty or challenge. To take this work further a game could be designed from scratch giving total control to the leader of that research, and then it would be possible to totally eliminate any difference in a game except for the sound design.
Several different sound designs with different qualities and could be constructed for the same level within a game. For example a level could have one sound design with very loud weapons and quiet VO and one sound design with loud VO and quiet weapons. The difference between those sound designs could either prove or disprove the information provided by this research.
8. Conclusion
This research found that the most important sound to the subjects in this test perception of
difficulty was the VO sounds as they where the most frequently mentioned sounds by both the
committee and the test subjects followed by the weapon sounds that was mentioned second by
both the committee and the test subjects. It was suggested that the use of loud weapons might
interfere with the other sounds such as the more important VO sounds that may lead to the
game being perceived as more difficult.
9 References
Collins, K. (2013). Playing with sound a theory of interacting with sound and music in video games. The MIT Press.
Ekman. I (2005, December) Meaningful Noise: Understanding Sound Effects in Computer Games.
Paper presented at the 2005 conference on digital arts and culture in Copenhagen, Denmark:
IT University!Press.
Jørgensen, K. (2011). Time for New Terminology? Diegetic and Non-Diegetic Sounds in Computer Games Revisited. In M. Grimshaw (Ed.), Game sound technology and player interaction concepts and developments (pp. 78-97). Hershey, PA, New York: Information Science Reference.
Laura Ermi, Frans Mäyrä (2005) Fundamental components of the gameplay experience:
Analysing immersion. Proc. DiGRA,
Lindskog, S.(2013). Computer Game Sound and Flow Experience: A Comparison of Diegetic and Non-diegetic Navigation Sound Cues in Games. (Kandidatuppsats/Bachelor’s Essay).
Departments of Arts, Communicatin and Education. Luleå University of Technology. Piteå Metacritic - Movie Reviews, TV Reviews, Game Reviews, and Music Reviews. (n.d.).
Retrieved May 28, 2015, from http://www.metacritic.com/
Walker, B. N., & Lindsay, J. (2006). Navigation performance with a virtual auditory display:
Effects of beacon sound, capture radius, and practice. Human Factors, 48(2), 265-278
9.1 Data points
Thread: Best games that you can play without sound (muted)? (n.d.). Retrieved January 19, 2015, from http://www.psu.com/forums/showthread.php/289498-Best-games-that-you-can-play- without-sound-(muted)
PC games I can play with no sound? (n.d.). Retrieved January 19, 2015, from
http://www.giantbomb.com/forums/general-discussion-30/pc-games-i-can-play-with-no-sound-
519605/
Battlefield 3. (n.d.). Retrieved March 4, 2015, from http://www.metacritic.com/game/xbox- 360/battlefield-3
Battlefield: Bad Company 2. (n.d.). Retrieved March 4, 2015, from http://www.metacritic.com/game/xbox-360/battlefield-bad-company-2
Bulletstorm. (n.d.). Retrieved March 4, 2015, from http://www.metacritic.com/game/xbox- 360/bulletstorm
Call of Duty: Black Ops. (n.d.). Retrieved March 4, 2015, from http://www.metacritic.com/game/xbox-360/call-of-duty-black-ops
Crysis 3. (n.d.). Retrieved March 4, 2015, from http://www.metacritic.com/game/xbox-360/crysis-3
Payday 2. (n.d.). Retrieved March 4, 2015, from http://www.metacritic.com/game/xbox- 360/payday-2
StatPrimer (Version 6.4). (n.d.). Retrieved March 11, 2015, from http://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pfd
9.2 Software
HOFA-Plugins (2015): 4U Meter Fader & MS pan Electronic Arts (2011): Battlefield: 3
Electronic Arts (2010): Battlefield: Bad Company 2 Blue Cat Audio (2015): Bluecat FreqAnalyst Electronic Arts (2011): Bulletstorm
Activision (2010): Call of Duty: Black Ops Electronic Arts (2013): Crysis 3
505 Games (2013): Payday 2
Avid Technology, Inc: (2014). Pro Tools 11
10. Appendix
10.1 Appendix 1 answer form for the pre-study
1 to 10
How much experience do you have with the game?
1. Never
played it 10. Played it a lot
How comparable are the controls to the reference game?
1. Very
different 10. Very similar
How comparable is the difficulty to the reference game?
1.much easier 10. Much more difficult
How comparable are the tasks to the reference game?
1. Very
different 10. Very similar
List up to ten sounds that influenced the
gameplay most.
1
2
3
4
5
6
7
8
9
10
10.2 Appendix 2 Comparison Calculation
𝐶𝑜𝑚𝑝𝑎𝑟𝑖𝑠𝑜𝑛 𝑆𝑐𝑜𝑟𝑒 = q2 + q3 + q4
q2 was calculated by adding the score all four member of the committee answer on the question “How comparable are the controls to the reference game?”
𝑞2 = 𝑞2
!"!#"$ !+ 𝑞2
!"!#"$ !+ 𝑞2
!"!#"$ !+ 𝑞2
!"!#"$ !q4 was calculated by adding the score all four member of the committee answer on the question “How comparable are the tasks to the reference game?”
𝑞3 = 𝑞3
!"!#"$ !+ 𝑞3
!"!#"$ !+ 𝑞3
!"!#"$ !+ 𝑞3
!"! !" !q3 was calculated by
𝑞3 = 20 − ( 5 − 𝑞4
!"!#"$ !!
) − ( 5 − 𝑞4
!"!#"$ !!
) − ( 5 − 𝑞4
!"!#"$ !!
)
− ( 5 − 𝑞4
!"!#"$ !!
