Before looking at the specifics of VoiceXML technology, it's a good idea to first consider the reasons why voice applications are being deployed. Some of the reasons are due to limitations of other application types, while others result from core benefits that voice solutions provide. Let's start with one of the most compelling reasons, accessibility.
There are more than 1 billion telephones in the world. This far exceeds the number of computers with Internet access and dwarfs the number of Internet-enabled mobile devices. Voice applications allow each of those telephones to act as an interface to the enterprise. In addition to universal accessibility, the medium of interaction is also desirable. Voice is the most efficient and preferred user interface for many applications, especially where a visual interface is impractical, such as when driving an automobile.
Cost savings is another factor. Since the users of the application already have access to telephones, there is no additional cost associated with purchasing and maintaining devices. Voice applications are device-independent as well, meaning you do not have to be concerned with developing multiple markup languages for multiple wireless network protocols for multiple devices. Finally, training costs are minimal; users will not have to be trained to use a new device with an unfamiliar user interface.
Voice applications benefit from the characteristics of the telephone, especially mobile phones. Mobile phones are small, inexpensive, easy to operate, and have a long battery life. This makes the phone an ideal platform for portable applications. As capabilities of mobile phones evolve, such as with the addition of location-based services, voice applications will quickly be able to take advantage of this new functionality.
The limitations of current user interfaces also provide reasons for developing voice applications. While WAP is a technology with lots of potential, many early users of WAP-based applications have been frustrated because the display screens are small, and inputting data using a keypad is slow and cumbersome. For devices with more advanced capabilities, such as wireless PDAs, the support for graphics and other rich content types are important features. The ideal solution will involve multimodal access to data. For example, to get weather information, you might speak the city name into the device to have the weather information for that city displayed on-screen of the device.
Voice does not have to be the only means of data access. In most cases, voice is used in conjunction with other application types. You might, for example, already have a smart client application for which you want to provide an easy way to access real-time data without requiring a wireless connection to synchronize the data. Offering a voice solution will provide an effective way to extend your enterprise applications to both existing and new users alike.
Finally, we consider the area where voice applications are used most often. Call centers have been using Interactive Voice Response (IVR) systems for some time. When handling large volumes of calls from people seeking similar sets of information, a voice system can be very effective. An IVR system allows a company to provide better service while reducing costs. Rather than providing limited hours of availability, with long hold times, voice systems can allow for immediate access to data 24 hours a day. In most cases, users can find the information they need without requiring human interaction. Unfortunately, user satisfaction with traditional IVR systems has been low. Rigid menus and slow response times often cause users to hang up or to press 0 to get a human attendant, rather than use the IVR system to its full benefit. This is just one of the many application areas that can be improved by a more flexible voice solution in VoiceXML.