Journal of Sonic Studies, volume 6, nr. 1 (January 2014)Iain McGregor; Phil Turner; David Benyon: USING PARTICIPATORY VISUALISATION OF SOUNDSCAPES TO COMPARE DESIGNERS’ AND LISTENERS’ EXPERIENCES OF SOUND DESIGNS
3.1 Design 01: Auditory Display
Auditory displays have been defined by Kramer (Kramer 1994) as an interface between users and computer systems using sound and are considered a natural extension of the way in which sound is used in the physical world. Auditory displays differ from auditory interfaces in that they operate unidirectionally. An interface allows audio to be used as input as well as an output, but does not require audio to be used as an input, whereas a display provides only output (McGookin and Brewster 2004). Speech interfaces are a specialist type of auditory interfaces that are predominantly confined to speech (Raman 2012). Auditory displays can be split into the user interface audio and audio used in visualisation. User interfaces include earcons, auditory icons, sound enhanced word processors (text to speech), and other applications, whilst sound in visualisation includes audification, sonification, and auralisation (Vickers 1999).
The sound events for the auditory display had been designed for a large manufacturer of electrical appliances for a variety of their products (Audio 1). The designer recorded no spatial cues, as the sound events were tested in isolation rather than within products (see Table 3). The designer made limited use of the material and interaction attributes, recording this information for only 9 of the 32 sound events. However, all of the other attributes were applied (see Figure 2). The majority of the sound events were considered by the listeners to be informative (square) and clear (opaque) (see Figure 3). Three of the sound events that were considered to be pleasing by the designer were found to be displeasing by the listeners (border width). There is a clear difference between the designer’s and listeners’ classification of music (musical notes symbol) and sound effects (loudspeaker symbol), with the designer considering the majority of sound events to be music, possibly due to the prominent use of earcons, which are often considered to be musical in nature by designers. The listeners predominantly classified these sound events as sound effects. They considered the aesthetics of the sound events to be more evenly distributed than the designer, who considered more to be either pleasing or displeasing. The listeners also classified more sound events as neutral than the designer, who considered the majority to be positive (emoticons).
As an auditory display, the sound design might be regarded as successful, as 26 out of the 27 sound events that were classified as informative by the sound designer were also classified as informative by the listeners (see Table 4). Similarly, 31 sound events were classified as clear by the listeners. The 3 sound events that were rated by the listeners as displeasing (AR, AT and BD) along with the 2 that were found to be uninformative (AT and AX) might benefit from further review. The major difference in the listeners’ and designer’s rating of the auditory display was in terms of the sound events being considered as sound effects rather than music by the listeners. The similarities were far more prevalent, especially in terms of the Temporal, Spectral, Dynamics, Content and Clarity attributes. This might mean that listeners did not fully appreciate the hierarchical associations that are inherent in earcon design. Listeners may perceive each earcon as a separate sound effect, which would require them to learn each icon individually, rather than recognise musical similarities.