Design and Usability Testing of an Audio Platform Game for Players with Visual Impairments.

Abstract: This article reports on the evaluation of a novel audio platform game that creates a spatial, interactive experience via audio cues. A pilot study with players with visual impairments, and usability testing comparing the visual and audio game versions using both sighted players and players with visual impairments, revealed that all the participants played the audio platform game successfully. ********** Aided by advances in computer graphics technology, the video game industry has experienced strong growth in recent years, earning $17.9 billion in 2007 alone (Boyer, 2008). Similar improvements in audio technology have encouraged the development of a growing number of dedicated audio-only games (see, for example, ) that use text, button presses, joysticks, or speech as inputs and provide recorded or synthesized sound or speech output (or both) to "display" the content of the game. However, despite efforts by the United Nations (1994) to encourage universal access to recreational and leisure activities for persons who are visually impaired (that is, those who are blind or have low vision), most games that have been developed for this population are still simplistic; persons who are visually impaired would welcome a wider variety and higher complexity of entertainment options (van Tol & Huiberts, 2006). In addition to their potential entertainment value, games may also provide a framework for motivating students to learn, as was discussed in a report on educational games by the U.K.-based Teachers Evaluating Educational Media group, and these games must remain accessible or risk excluding persons with disabilities (International Game Developers Association, 2004; McFarlane, Sparrowhawk, & Heald, 2002). Originally developed in the 1980s, the platform game genre has considerable potential for conversion to an audio-only format. Platform games are set in a two-dimensional (2-D), side-scrolling world with a user-controlled character that hops on or over objects, such as obstacles and platforms, to reach a goal. The player needs to use strategic thinking to traverse multifloor platforms to reach a goal, and quick reactions to complete such tasks as jumping over an approaching opponent. Although state-of-the-art platform games use three-dimensional (3-D) graphics that often bar persons with visual impairments from enjoying them, many players with visual impairments are able to take pleasure in playing 2-D platform video games, such as Super Mario Bros., despite being forced to adapt to the media by using their limited vision or by memorizing the layout of levels through trial and error. Creating an audiocentric platform game requires translating the inherently 2-D spatial game world into audio cues that effectively represent the game's objects (the characters, opponents, and obstacles) and their spatial relationships. An audio-only platform game (Super Liam, 2008) already exists; however, it significantly simplifies many of the elements that are typical of this game genre that make them challenging and interesting to play. For the design of a more challenging audio-only platform game, we turned to guidelines for the creation of audio games that were proposed by Gadenfors (2002) and to the field of auditory displays and interfaces. One type of auditory display, sonification, is based on research on auditory perception (Bregman, 1990), and a general theory for this technique has emerged over the past decade (Barrass, 2003; Stevens, 1996; Walker & Kramer, 2005). In sonification, nonspeech audio is used to translate information on maps into sound (Kramer et al., 1999). For example, a series of numbers can be mapped onto a series of pitches for auditory graphs, with the upward or downward shifting of a sound source's pitch mapped as a rise or fall of the source's elevation (Flowers, 2005). Another example of sonification is auditory icons (Gaver, 1988), which use prerecorded sound "caricatures" of real-world sounds that link a concept to the sound it produces; for example, a barking sound communicates the general concept of a dog. …