This article is the 2nd part of a serie investigating Mark Grimshaw’s PhD Thesis “The Acoustic Ecology Of The First-Person Shooter”. My previous post discussed some of the main terminologies that Mark Grimshaw explores and this post will continue by dicussing the acoustic spaces that are formed when game player interacts as a part of the acoustic ecology.

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.