Technology Trends

What’s new with VoiceXML 2.0?

By Dr. James A. Larson

While the W3C Voice Browser Working Group is focused on enhancing the VoiceXML 2.0 language, the VoiceXML Forum is working to improve the community of VoiceXML developers. Here are brief summaries of ongoing activities—some available today, others available in the future.

Today: VoiceXML Developer Certification Test

The VoiceXML Forum has announced the availability of the VoiceXML Application Developer Certification Test. This test certifies that developers have important knowledge and skills necessary to design, develop, deploy and maintain speech applications using the W3C Speech Interface Framework languages of VoiceXML 2.0: Speech Synthesis Markup Language 1.0, Speech Recognition Grammar Language 1.0, Semantic Interpretation Language 1.0, ECMAScript 262/327 and Call Control XML Language 1.0. The test sets the standard for knowledge and training required to develop speech applications. The VoiceXML Application Developer certification test benefits both employers and their employees:


Today: The VoiceXML Education Exchange

VoiceXML resources are available to instructors of college and university courses involved in VoiceXML training and research. These resources include:


Future: VoiceXML 2.1

To determine which features to include in VoiceXML 2.1, the W3C Voice Browser Working Group identified eight new features implemented, documented and deployed by individual VoiceXML 2.0 vendors. VoiceXML 2.1 is backwards compatible with VoiceXML 2.0, so all VoiceXML 2.0 applications should continue to run under VoiceXML 2.1. VoiceXML 2.1 features includes the following:


·         blind — connect the calling party to another telephone line. The VoiceXML 2.1 application does not remain in the connection and does not monitor the outcome. (This corresponds to the VoiceXML 2.0 <transfer> attribute bridge = “false”.

·         bridge — connect the calling party. The VoiceXML 2.1 application remains in the connection and listens for words included in the <grammar> element. (This corresponds to the VoiceXML 2.0 <transfer> attribute bridge = “true”.)

·         consultation — similar to a blind transfer except that the platform monitors the progress of the transfer and if the connection cannot be established, then the session remains active and returns control to the application.

Future: V3

The W3C Voice Browser Working Group is working on a new speech processing architecture code named V3. V3 will support the following features:

The Voice Browser Working Group expects to publish the first working draft of the V3 architecture by the end of this year.


Dr. James A. Larson is Manager of Advanced Human Input/Output at Intel Corporation and author of the book, Voice XML - Introduction to Developing Speech Applications. He can be reached at and his Web site is