Diegesis and Immersion
When designing games – the aim is to enhance the player and immerse her/him into the game play. Looking at the subject from an aural perspective the focus is the player, as s/he is has several functions when forming the acoustic ecology in game. It is the player that:

• Immerses in the acoustic ecology
• Participates in the acoustic ecology
• Performs to create, sustain and transform the acoustic ecology

Previous work on digital game audio has borrowed the terminologies of diegetic and non-diegetic sounds from film theory and tried to put them in context of digital computer games.

• Diegetic sounds refer to sounds that are closely connected with the narrative of visuals – like for instance – a man stand in front of a door, raises his right hand and bangs on the door. The viewer then hears the sound of a hand knocking on a thick piece of wood imitating the action taking place in the visuals
• Non-diegetic sounds refer to sounds that do not have a direct connection to the narrative in the visuals such as for instance a music score.
• Another theorist, Curtis (1992), prefers the terms ‘isomorphic’ and ‘iconic’ referring to the way musical instruments are used in for instance Disney cartoons.

Looking at music as a non-diegetic sound, Grimshaw suggests that music in FPS games can have a considerable effect on actions experienced by player, as FPS game music exists in between diegetic and non-diegetic sounds. An example of this gray area in between diegetic and non-diegetic sounds is for instance a player who runs through a level and shoots the enemies in such a rhythmic manner that her/his gunshot executions are synchronised with the rhythmic patterns in the music score.

Because of the complexity of a digital game play in terms of player’s interaction with the game world and because of the multiple diegetic sound outcomes – Grimshaw suggests that diegetic sound in digital games should

be defined as the sound that emanates from the game play environment, objects and characters and that is defined by that environment, those objects and characters.

By this he means that it is difficult to define the sounds as being strictly diegetic or non-diegetic as they are all at all times subject to change, as player interacts in the acoustic ecology. In contrast to the above, the non-diegetic sounds can be defined by sound events that occur prior to and following game play, like for instance UI sounds, game and level configuration menus and music score, that gives the player specific cues on points gained, or that s/he is in or outside the game, or that s/he has completed a mission.

According to Grimshaw the problem of using film sound terminology in game audio lies in the major differences between the two media. We can roughly say that in a digital game:

• Sounds can have an impact on the actions of a player
• Sounds are not necessarily heard by all the players at the same time

Grimshaw suggests a solution for creating a distinction between the diegetic sounds heard during game play, by introducing the following categories:

• Ideodiegetic sounds – This terminology refers to diegetic sounds that can only be heard by one player, which includes all sounds that derive from within that particular player’s resonating space – sounds that come from character or other sources in the area. Ideodiegetic sounds are furthermore classified into: exodiegetic sounds which are sounds heard by player that are not triggered by player and kinediegetic sounds which are sounds that are triggered and heard by player
• Telediegetic sounds – This terminology refers to a sound that is heard by and responded to by one player, where the actions of that response has a consequence for another player later on.

All diegetic sounds in the acoustic ecology have an importance and consequence for player, as player has to interact and react upon events and objects within the game world displayed on screen.

Perceptual Realism & Immersion
The use of authentic audio recordings, of for instance real weapons, when creating the weapon sound effects for a FPS game, is currently the only way for game designers to simulate or emulate a ‘real world realism’ in a 3D graphic game environment.

Sound is an illusory and real-time 3D event that player acts upon during game play. The use of caricature and convention sounds, rather than authentic sounds, in the resonating spaces establishes the paraspaces in which player has to act on and it is the player’s task to make the distinctions between virtual and real sounds.

The aim of a FPS game designer is to make the player believe that s/he is within the game environment. Sound is one of the key factors to immersion in 3D virtual environments and the creation of ‘perceptual realism’. It is the use of sound, with its physical 3-dimensionality, in the digital media that creates the possibility for player to mentally and physically immerse within the acoustic ecology of game.

The Acoustic Ecology of the FPS Game
Players interaction and immersion within the acoustic ecology is based on players prior experience from outside and inside the game.

A player who hears a music piece on a specific level might for instance interact within the acoustic environment differently depending on various facts.

• If player is musical: S/he will use different modes of listening depending on how familiar s/he is with that particular piece of music style or genre

• If player is new to the game: Player might use the music to navigate and explore the level to find out what kinds of affordances there are in the area to prioritize

• If player is experienced: The music is appreciated as a keynote sound – meaning that its main function is to immerse player into the 3D game world, indicating the spaces and areas player is moving within.

The acoustic community is a place where acoustic information is exchanged in between the inhabitants. An example is ,for instance, a player that hears a signal sound of an action that s/he does not see visually, which turns out to have a consequence for her/his further game play.

According to Grimshaw the acoustic ecology is a system and a cycle that is dependent on player’s controller inputs – a system that changes with time as player interacts and gives response to the soundscape.

CONCLUSION

The thorough conceptual framework gives an understanding of sounds, soundscapes, acoustic spaces and their functions used in FPS games and how they effect the player’s gaming experience.

Mark Grimshaw investigates with his thesis how players interact in the acoustic ecology of the gaming environments alone and with other players. He examines player’s audio experience and immersion into the soundscapes of the 3D world as a physical event that is open for interpretation. He also argues why audio is an important part of player’s gaming experience in FPS games.

One could also argue that Mark Grimshaw’s thesis is giving some of the answers to why audio is an important part when improving player’s gaming experience, as he argues that sound is the only true physical dimension of the imitated 3D world displayed on a computer or TV screen.

There are also the implications of how the soundscape is designed to be perceived in contrast to how the soundscape is actually perceived or interpreted by player – forming the acoustic ecology. This is again based on player’s prior gaming, social or cultural experience.

The thesis “The Acoustic Ecology Of The First-Person Shooter” is a thorough analysis of the FPS game genre, which also gives a conceptual framework and tools for analysing digital game audio used in other game genres.

ACOUSTIC SPACES

When discussing game audio and acoustic spaces – the dimension of space and time are important factors. Acoustic spaces in acoustic ecologies can be understood in two ways:

• A space with physical parameters of sound propagation
• A specific location in a game; like a harbour or dungeons

Looking at the spatial dimensions of an acoustic ecology, Grimshaw suggests the terms: resonating spaces and paraspaces.

A sound event in a space can be a perceived as a combination of many functions and meanings, as it depends on player’s interpretation and socio-cultural experience. Grimshaw makes the following distinctions between the perceptions of spaces:

• 1st perception of space: Sound is perceived as a 3-dimensional event and is therefore the primary medium that gives player a perception of the illusionary space. The illusionary space being represented by a 3D graphic environment and displayed on a 2D TV or computer screen.
• 2nd perception of space: The 3D sounds are triggered by the game engine and distributed with the images and animations displayed on screen. The perceived sounds that represent a real acoustic resonating space is then combined with the images displayed on screen, creating a second virtual space. This gives the player a perception that the objects on screen exist within the virtual resonating spaces. Meaning that the real-time created acoustic resonating space gives player a perception of an affordance of objects that exist within the 3D game environment.

Looking at the above there are two spaces formed around the player. These spaces change according to player’s actions, continuously creating new affordances to player. This is one of the perceptual keys to player’s immersion with the game world.

Resonating spaces
A resonating space involves the physical properties and functions that are similar to an acoustic space with parameters such as reverberation, localization and sound propagations. By using the term resonating space Grimshaw introduces the concept of acoustics: sound that propagates as mechanical waves travelling from sound source through air. Sound as a physical event that propagates and expands in the volume of the containing space and reflective surfaces.

But the fact is that the physical dimensions of an acoustic wave is an illusion, as the sound source is the output from the TV speakers or headphones and not the actions player performs in the 3D game world. So according to Grimshaw, a resonating space is a physical space dimension that is:

• A physical, acoustic representation of the 3D game world
• Dynamic and changes over time according to player inputs on controller

Two important parameters that can not be ignored, when discussing resonating spaces regarding spatiality and sound are: volume and time. They are important because of the following:

• Volume is a physical parameter. It can be represented by the Cartesian coordinate system and can therefore also be perceived as the physical representation of the Cartesian coordinate system that is coded in the game engine
• Time is the temporal dimension of a sound propagating through air as mechanical waves

When looking at the physical dimensions of a game player and the perceived acoustics during game play, we acknowledge that the physical reality is reversed.

In the real world we locate sound sources by physically moving our heads, but in a gaming environment this not possible. The only physical body parts that player moves during game play are the hand movements on the controller – and occasional whole-body reactions to unexpected sounds.

The in-game sound sources change position or volume in relation to player’s position in the 3D game environment – and not the opposite which is the case in the real world, where we physically move our body to locate a sound source.

This tells us that the player is the centre of the gaming event as an immobile figure and s/he is in control of the acoustic space represented on screen as a 3D world.

Some other physical dimensions and parameters that are important to have in mind when considering player’s control of the acoustic space are:

• Low frequency sounds – Low frequency sounds are difficult to localize for the human ear. But during the audio production of sound effects, such as guns and explosions, low frequencies below 1500 Hz are usually boosted to make the effect more ‘powerful’. Because of the difficulty in locating the sound source, the player is then involved in the sound itself and not its relation to the 3D game world. This also contributes to the fact that player’s audio experience is a perception of a closed acoustic space.
• Sound as a true physical event - Sound events are the only true three-dimensional components of the virtual game world with the physical parameters of time, amplitude, speed and volume. This is therefore also the only physical dimension from which player can immerse into the virtual game world.

Paraspaces
Grimshaw refers to paraspaces as the spatial dimension within the acoustic ecology that provides affordances involving player to experience location, time, cultural or social factors in game.

During a FPS game, a player will interact with the 3D world in many locations such as the docks, a harbour, dungeons, hotel lobby or a marketplace. A space that indicates a distinct location may have different functions and significations in reality. This also means that the perception and understanding of the affordances in a paraspace depends on player’s cultural and social experience.

Grimshaw gives the example of a paraspace scenario including sounds such as: car traffic, Big Ben and people talking English with a Cockney accent. Based on the cultural experience of player, s/he will then understand the location as being London in United Kingdom. If player has never been in United Kingdom, s/he will then maybe understand the paraspace as just being a big city and not being able to point out the exact country.

Ambience and the use of ambient sounds on locations in games may sometimes be musical or they may be a combination of musical content and sounds together. This means that ambient sounds used in paraspaces may be real or they may be imaginative and ‘not real’. The player will then again interpret the perceived location or ‘paraspace’ relying to her/his cultural experience – or gained experience during training in game.

There is also the function of real-time signal processing to consider when discussing paraspaces. When a reverberation effect is added to the sounds it is the intention of audio designer to give player a sense of the physical dimensions of the paraspace – such as a cathedral, cavern or hallway.

Overall a paraspace can be divided into locational and temporal paraspaces. The temporal paraspace is then divided even further by Grimshaw into: temporal period and temporal progression.

To describe the temporal paraspace – Grimshaw introduces four terms describing sounds with spatial functions:

• Choraplasts – Audio that contributes to the perception of a resonating space
• Topoplasts – Audio that indicates a location and therefore has a paraspatial function
• Chronoplasts – Audio giving the perception of time progression
• Aionoplasts – Audio that sets the game world in a ‘historical’ frame – a past, present, future or immediate timeframe

At the same time it should be remembered that the above terms are not static, as their functions and meanings can change based on player’s actions or interpretations. As the acoustic space is mediated by player perception and players categorization of sounds within the resonating space, the perception of sounds will be subject to change.

Summary
This post is the 2nd in a serie of articles dealing with Mark Grimshaw’s PhD Thesis “The Acoustic Ecology Of The First-Person Shooter”. An important part of game players immersion in the virtual 3D gaming environment is the physical dimensions of audio. Acoustic spaces can be perceived from the following perspectives:

• A resonating space, where: Sound is a true physical event that travels from source through air as mechanical waves and expands in the containing volume of space and reflective surfaces
• A paraspace, where: Sound as a location indicates the place a player is navigating within. A paraspace can at the same time be divided into two categories: temporal period and temporal progression. The temporal progression indicating that time is moving forward and the temporal period indicating the history of a location.

My next post will be the 3rd and last article in this serie exploring Grimshaw’s views on game player’s diegesis and immersion into the acoustic ecology of the virtual 3D gaming world.