3.1: Types of sonification.

One taxonomy of sonification (for others, see Fitch & Kramer, 1994; Nees & Walker, 2009), distinguishes between five functions of sonification: alerting, status indication, data exploration and, art and entertainment (for more in-depth reviews, see (Hermann et al., 2011; Walker & Kramer, 2004).

Alerts refer to sounds that notify the listener that an event has, or is about to occur, and that something in the environment requires their attention. These range from rather simple, low-information alerts like a door-bell, indicating someone is at the door; to more complex alerts that attempt to convey more information, like warning systems in a helicopter cockpit indicating a range of telemetry and avionics data (Edworthy, Hellier, Aldrich, & Loxley, 2004) or forward collision systems in modern cars (P. Bazilinskyy, Petermeijer, Petrovych, Dodou, & De Winter, 2015; Jamson, Lai, & Carsten, 2008).

Closely related to the alerting function, is the status or progress indicating function. In this case a listener monitors a constant sound for small changes that indicate a change in status or progress update. For example, using auditory displays to monitor for changes in blood pressure (T. Watson & Lip, 2006), internet network traffic (Debashi & Vickers, 2018; Vickers, Laing, & Fairfax, 2017), or telephone hold time (Garcia, Peres, Ritchey, Kortum, & Stallmann, 2011; Kortum, Peres, Knott, & Bushey, 2005).

Data exploration is likely the function most closely associated with the term sonification. Simply put, sound is used to represent data in a way that enables the listener to recognize or search for patterns. This includes auditory graphs, created to summarize and communicate a set of data with known patterns (e.g., Flowers, 2005; Stockman, Nickerson, & Hind, 2005; Walker & Mauney, 2010), or as a way to explore more complex data sets to facilitate interpretation and exploratory analyses (e.g., Grond & Hermann, 2014; Stanton, 2015). Data exploration and pattern recognition will be discussed in greater detail below, however data sonification has been used successfully across a range scientific disciplines from astronomy (Diaz Merced, 2013; W. L. Diaz-Merced et al., 2011) to the social sciences (Dayé & de Campo, 2006). To give just one example, Pereverzev, Loshak, Backhaus, Davis, & Packard (1997) used sonification methods to discover quantum oscillations between two weakly coupled reservoirs of superfluid helium 3, confirming previous theoretical predictions.

Finally, sonification can be used for entertainment, art, sports, and leisure. That is, sonification can be used for artistic expression and/or recreation. This final category includes the creation audio-only versions of games (i.e., sonified games) like Tower of Hanoi (Winberg & Hellstrom, 2001) and Tic-Tac-Toe (Targett & Fernstrom, 2003), as well as using sonified feedback to improve performance in sports like rowing (Dubus & Bresin, 2015) and figure-skating (Boyd & Godbout, 2010). Perhaps unsurprisingly, musical composition is another popular use of sonification methods. Here, often large data sets (e.g., weather changes, shark movements, seismic data) are mapped to musical representations to create works of art (e.g., Ballora, 2014; Parkinson & Tanaka, 2013; Quinn, 2001, 2012). In one demonstration, for example, a century of weather data was transformed into compositions for cello and string quartets to describe and communicate climate change (George, Crawford, Reubold, & Giorgi, 2017). In another, DNA sequences were used to compose music in an effort to summarize complex microbial ecology data (“Microbial Bebop”; Larsen, 2016). The line between artistic expression and data display is obviously blurred here. However, in these cases, the primary goal is to create an aesthetically pleasing work of art and communicating an interpretation of the data, if considered at all, is secondary.