VoiceXML for Web-based distributed conversational applications
Bruce Lucas · Communications of the ACM · 2000
VoiceXML replaces the familiar HTML interpreter (Web browser) with a VoiceXML interpreter and the mouse and keyboard with the human voice.Development of speech services has been hindered by a lack of easy-to-use standard tools for managing the dialogue between user and service.Interactive voice-response systems are characterized by expensive, closed application-development environments.Lack of tools inhibits portability of applications and limits the availability of skilled application developers.Consequently, voice appli-cations are costly to develop and deploy, so voice access is limited to only those services for which the business case is most compelling for voice access.Here, I offer an introduction to VoiceXML, an emerging standard XML-based markup language for distributed Web-based voice services, much as HTML is a language for distributed visual services.VoiceXML brings the power of Web development Bruce LucasUntil recently, the Web delivered information and services exclusively through visual interfaces on computers with displays, keyboards, and pointing devices.The Web revolution largely bypassed the huge market for information and services represented by the worldwide installed base of telephones, for which voice input and audio output provide the sole means of interaction. VoiceXMLfor Web-based distributed conversational applications and content delivery to voice-response applications, freeing developers from low-level programming and resource management.It also enables integration of voice services with data services, using the familiar client/server paradigm and leveraging the skills of Web developers to speed application development for this new medium.VoiceXML 1.0 was developed by the VoiceXML Forum (see www.voicexml.org),which released it in March 2000, and was accepted by the World Wide Web Consortium (W3C) two months later as the basis for developing a W3C dialogue markup language (see www.w3.org/Voice/).The initial version of the language included robust support for basic state-based dialogue capabilities, using a design with simple form-based natural language capabilities that leaves room to grow as the technology evolves.(You can find the VoiceXML specification at www.voicexml.organd a free implementation for personal use at www.alphaworks.ibm.com/tech/voic-eserversdk.)