[Note: This content is adapted from the chapter "Sound as Information: An Introduction to Auditory Display" that I wrote for the book Audio Anecdotes II]
In order to understand how sound can be applied effecitvely in the design of products, it is essential to understand the mechanics of sounds itself.
Although physical acoustics can get quite technical and mathematical, the underlying premise is quite simple, and was succinctly put by Bill Gaver (Gaver, W.W. (1993). What in the world do we hear?: An ecological approach to auditory event perception. Ecological Psychology, 5, 1-29) in the following statement:
“a given sound provides information about an interaction of materials at a location in an environment”
This statement has the following implications:
- Sound, by definition, requires the movement of an object or objects. The particular materials and interactions involved will determine the characteristics of the resulting sound.
- Beyond the materials involved and their interactions, sound informs listeners about location. It is our ability to localize an event via its sound that enables us to react appropriately. A sound that is distant will elicit a different reaction than a sound that is nearby. Likewise a sound that occurs behind will cause a response different than a sound that is in front of a listener. The ability to localize information via sound is arguably the greatest asset of hearing.
- The last part of Gaver’s definition refers to the interaction of materials at a location in an environment. Sound informs the listener about an event-taking place at a certain location within a certain kind of environment. There are a number of ways in which the environment may alter the acoustical characteristics of a sound. The most obvious example is an echo, where the size and reflectivity of the environment allow for audible repetitions of a sound, with each successive repetition weaker than the previous. Any environment (with the exception of a completely open or absorptive space) will reflect sound waves and create repetitions.
It should be evident by now that any sound can reveal a great deal of information to a listener: the interaction of objects involved in creating the sound, the location of the sound with respect to the listener, and the spaciousness and composition of the environment.
The richness of information inherent in auditory perception can be leveraged to use sound as a more effective means to communicate information. To do so successfully, requires a fuller understanding of how sound can and has been used to display information.
