2 Effective messaging for audio instructions

2.0 Overview

This section describes how messages can be constructed to make audio instructions as effective as possible. Other researchers’ work [1, 2, 3] has been used as a basis for the analysis of the different components of an audio instruction.

2.1 The components of an audio instruction

The vital components of an audio instruction are the following:

• Verbs, which communicate the action required. They are mainly about movement but can convey other types of actions, such as “press a button.” Useful verbs for instruction include walk, turn, take, go, follow, keep walking, keep following, and press.
• Orientation information This information communicates the user’s current location in relationship to their surroundings. Examples include: there are, it is, you are now at, the trains leave, you are approaching, you are halfway, when inside.
• Environmental features that comprise:
  • Segments are distinctive areas in an environment. As mentioned above, it is helpful for vision impaired people to break the route down into sections and announce the forthcoming segments. For the segments of a Mainline Rail or Metro station see Section 4.2.1.
  • Pathways are corridors, ramps, escalators, stairs or lifts (elevators) that vision impaired people can use to get to their destination.
  • Decision points such as crossings or intersections are where more than one pathway meets and vision impaired people need to be instructed about the direction they need to take when they reach these decision points.
  • Landmarks as in Section 2.4 “Landmark and clues”; vision impaired people can identify many different landmarks and their choice of landmarks may be subjective.
  • Objects that require interaction. The call button on a lift is a typical object that requires users to interact with it in the environment.
  • Directional delimiters are words and phrases that communicate direction. They usually follow a verb. Some commonly used examples are: forward, up, down, to, right, left, through, in front (of you), the left (one), 45 degrees to your right, turn at 2 o’ clock, between, on, on your left, at the platform, for your destination, from (your left)
• Countable delimiters are words or phrases that count numbers to navigate to an object or an environmental feature. Some commonly used examples are: the first (corridor), the next (crossing).
• Sequential delimiters are words or phrases that limit the relationship of one object to another. Some commonly used examples are: after (the gates), at the bottom of (the escalators), at the next (passage).
• Descriptive delimiters are words or phrases that describe an object or an environmental feature. Some commonly used examples are: the up (escalator); the lower (concourse); the wide (gate).

To better understand these, below are some examples of how an audio instruction is structured based on combinations of the various elements above.

Audio instruction example 1

The instruction comprises the following elements:

Verb (i.e. turn), directional delimiter (i.e. left), verb (i.e. take), environmental feature is the pathway (i.e. the escalator), directional delimiter (i.e. down), directional delimiter (i.e. to), environmental feature is the area/segment (i.e. the platforms), directional delimiter (i.e. the down), environmental feature is the pathway (i.e. escalator), state-of-being verb (i.e. is), directional delimiter (i.e. the one on the left).

Audio instruction example 2

The instruction comprises the following elements:

Sequential delimiter (i.e. at the bottom), environmental feature is the pathway (i.e. the stairs), verb (i.e. turn), directional delimiter (i.e. right), verb (i.e. walk), directional delimiter (i.e. forward), directional delimiter (i.e. to), environmental feature is the segment (i.e. the platform).

2.2 References

1. Allen, G. L. (2000). Principles and practices for communicating route knowledge. Applied cognitive psychology, 14(4), 333-359. (last accessed: 29 February 2016)
2. Kulyukin, V. A., Nicholson, J., Ross, D. A., Marston, J. R., & Gaunet, F. (2008). The Blind Leading the Blind: Toward Collaborative Online Route Information Management by Individuals with Visual Impairments. In AAAI Spring Symposium: Social Information Processing (pp. 54-59). (last accessed: 24 February 2016)
3. Nicolau, H., Guerreiro, T., & Jorge, J. (2009). Designing guides for blind people. Departamento de Engenharia Informatica, Instituto Superior Tecnico, Lisboa. (last accessed: 24 February 2016)