O’zaro ta’sirli interfeysni loyihalashda hisobga olinishi kerak bo‘lgan operatorning asosiy xususiyatlari

2.7 Vocal Interfaces
Vocal interfaces can play an important role in various contexts: with vision-impaired users; when users are on the move; more generally when the visual channel is busy. Examples of possible applications are booking services, airline information, weather information, telephone list, news. However, vocal interactive applications have specific features that make them different from graphical user interfaces. They are linear and non-persistent, while graphical interfaces support concurrent interactions and are persistent. The advantage of vocal interfaces is that they can be fast and natural for some operations.
Recently there has been increasing interest in vocal interfaces since vocal technology is improving. It is becoming more robust and immediate, without need for long training, and thus various its applications have been proposed in the mass market, e.g. vocal searches and map navigation by Google or Siri on iPhone. This has been made possible by providing the possibility of entering vocal input with audio stored locally and then sent to the server for speech recognition. Vocal menu-based navigation must be carefully designed: there is a need for continuous feedback in order to check the application state, it should provide short prompts and option lists to reduce memory efforts, and should support management of specific events (no-input, no-match, help). Although the logical structure of a graphical page is a tree, its depth and width are too large for vocal browsing. Figure 13 shows an example of a graphical user interface and represents its logical structure by using polygons with solid borders to indicate the main areas, and then dashed borders to indicate sub-areas inside them.

Figure 2.13: Logical structure of a graphical user interface
Figure 14 shows on the left a corresponding vocal menu automatically derived according to an algorithm (Paterno and Sisti,2011) in which the texts of the vocal menu items are derived either from elements id or from the section contents. On the right of Figure 14 there is an example of vocal dialogue that can be obtained from such a vocal interface.

Figure 2.14: Vocal version of the example user interface