Voice Application Development Using VoiceXML
When developing applications for mobile users, the tendency is to think automatically of an application installed on a PDA or wireless Internet access using a technology such as WAP. These are valid choices, and applications developed on these platforms meet the needs of millions of users each day. Handheld platforms currently have several problems from the user's viewpoint, though. Commonly heard objections include "Entering text on these devices is impossible," or "I can barely see the screen!" and "It's quicker to look up the weather in my newspaper than on my WAP phone!" All of these are valid points, and armies of developers are currently working on a variety of enhancements that will ease some of these problems. Given these current stumbling blocks, it makes perfect sense to include VoiceXML in your developer toolbox. Why? Because applications built using VoiceXML make use of a very comfortable user interface (the voice!) and can force users to step through applications using a structured decision tree. For simple tasks such as getting movie times, stock quotes, weather, and directions, many people feel more comfortable listening/speaking to a service than they do typing/reading while driving, walking, or working.
These projections from several leading industry analysts should help clarify the size of this market opportunity:
ResearchPortal.com finds that the percentage of U.S. wireless service users who use voice-centric devices will increase from 43% in 2000 to 72% in 2001. Between April and June, 2000, ownership of non–PC devices grew twice as fast among households without PCs than households with PCs. The largest growth in non–PC households is in wireless phones.
Allied Business Intelligence reports that there will be 4 million landline voice-portal users in North America in 2001. That number will mushroom to 17 million by 2005. North American mobile voice-portal users will grow from about 1 million users in 2001 to more than 56 million by the end of 2005.
Cahners In-Stat Group finds that wireless voice and data access will lead to an explosion in sales of mobile computing devices. By 2004, 51% of mobile computing devices will be wireless-enabled, and integrated phone modules (such as the phone module for the Handspring Visor) will be a force of change in the market.
All the information above was retrieved from allNetDevices' Market Research Section.
Clearly, analysts are convinced that voice technologies will not be completely replaced by WAP and other wireless data tools…in fact, voice applications will flourish! The VoiceXML Forum maintains the VoiceXML standard and was founded by AT&T, Lucent Technologies, Motorola, and IBM. In this article, I'll step you through the VoiceXML standard and explain the building blocks of a VoiceXML application.