Voice Browser Working Group Charter

The mission of the Voice Browser Working Group, part of the Voice Browser Activity, is to enable users to speak and listen to Web applications by creating standard languages for developing Web-based speech applications. The Voice Browser Working Group concentrates on languages for capturing and producing speech and managing the dialog between user and computer, while a related Group, the Multimodal Interaction Working Group, concentrates on additional input modes including keyboard and mouse, ink and pen, etc.

Summary Table

End date 31 January 2009
Confidentiality Proceedings are Member-only, but the group sends regular summaries of ongoing work to the public mailing list.
Initial Chairs Jim Larson, Scott McGlashan
Initial Team Contacts
(FTE %: 100)
Kazuyuki Ashimura, new hire
Usual Meeting Schedule Teleconferences: Weekly
Face-to-face meetings: 3 to 4 per year


The telephone was invented in the 1870s and continues to be a very important means for us to communicate with each other. The Web by comparison is very recent, but has rapidly become a competing communications channel. The convergence of telecommunications and the Web is now bringing the benefits of Web technology to the telephone, enabling Web developers to create applications that can be accessed via any telephone, and allowing people to interact with these applications via speech and telephone keypads. The W3C Speech Interface Framework is a suite of markup specifications aimed at realizing this goal. It covers voice dialogs, speech synthesis, speech recognition, telephony call control for voice browsers and other requirements for interactive voice response applications, including use by people with hearing or speaking impairments.

Some possible applications include:

Under previous charters, going back to 2000, The Voice Browser Working Group have created the W3C Speech Interface Framework suite of specifications, which includes:

In addition to the above, here is a list of documents produced by the Voice Browser Activity


All work items carried out under this Charter must fall within the scope defined by this section.

VoiceXML 2.1
VoiceXML 2.1 is an extension to VoiceXML 2.0 that provides 8 new features to VoiceXML 2.0. The Group plans to take VoiceXML 2.1 through to Recommendation status.
VoiceXML 3.0
VoiceXML 3.0 is the next major release of VoiceXML. VoiceXML 3.0 will provide powerful dialog capabilities that can be used to build advanced speech applications, and to provide these capabilities in a form that can be easily and cleanly integrated with other W3C languages. VoiceXML 3.0 will provide enhancements to existing dialog and media control, as well as major new features (e.g. multimedia prompts, VCR controls, speaker identification and verification, modularization, a cleaner separation between data/flow/dialog, and asynchronous external eventing) to facilitate interoperation with external applications and media components. The Group will create multiple profiles of VoiceXML 3.0 that enable subsets of VoiceXML 3.0 to target specific user cases. (e.g.,. handheld computers and cell phones with too few resources for full VoiceXML). The Group plans to continue work on VoiceXML 3.0, and plan to published several iterations of the document.
State Chart XML
SCXML 1.0 is a generic XML control language based on Harel State Charts. Although SCXML was designed as a control language for VoiceXML 3.0 and for Multimodal Interaction dialog management, SCXML may also be used for control other types of applications. The Group plans to take SCXML 1.0 through to Recommendation status.
Speech synthesis
SSML 1.1 enhances SSML 1.0 to better support widely spoken East-Asian, Indian and Middle Eastern languages in a manner that improves its usefulness in other languages as well. It also updates SSML 1.0 to be more consistent with PLS, SISR and expected VoiceXML 3.0 functionality. The Group plans to take SSML 1.1 through to Recommendation status. The Group may begin work on SSML 2.0 which will restructure SSML 1.1, enhance the <say-as> element, the role attribute, and possibly provide additional enhancements (for example, emotion elements).
Speech recognition grammars
This covers context free grammars and statistical models of speech, together with DTMF input. SRGS 1.0 for context free grammar is already a full Recommendation. The Group may resume work on N-Gram (statistical) model of speech.
Pronunciation Lexicon
Pronunciation Lexicon Specification (PLS 1.0) provides the basis for describing pronunciation information for use in speech recognition and synthesis, for use in tuning applications, e.g. for proper names that have irregular pronunciations. The Group plans to take PLS 1.0 to full Recommendation. The Group may enhance the role attribute, possibly with a registry.
Semantic interpretation for speech recognition
SISR 1.0 describes annotations to grammar rules for extracting the semantic results from recognition, either as XML or as a value that can be held in an ECMAScript variable. The target for the XML output is EMMA (Extensible Multimodal Annotation Markup Language) which is being developed in the W3C Multimodal Interaction Activity.
Telephony call control for voice browsers (CCXML 1.0)
CCXML 1.0 is an XML language for controlling connections, conferences, and dialogs in a Voice Browser context. The Group plans to take CCXML 1.0 through to Recommendation status. We may consider enhancing CCXML 1.0.
Maintenance work
The Working Group will be maintaining its existing (or soon-to-be) Recommendations: VoiceXML 2.0, VoiceXML 2.1, SRGS 1.0, SSML 1.1, SISR 1.0, PLS 1.0, SCXML 1.0, and CCXML 1.0. Maintenance takes the form of: responding to questions and requests on the public mailing list, issuing errata as needed and possibly publishing minor updates to the specifications.

Success Criteria


The following documents are expected to become W3C Recommendations:

The following documents are either notes or are not expected to advance toward Recommendation:

The following documents may be revised depending upon the interest of working group members:




This Working Group is chartered to last until 31 January 2009. The first face to face meeting after re-chartering will be held in May or June 2007.

Here is a list of milestones identified at the time of re-chartering. Others may be added later at the discretion of the Working Group. The dates are for guidance only and subject to change.

Note: The group will document significant changes from this initial schedule on the group home page.
Document Requirements First Public Working Draft Last Call Working Draft Candidate Recommendation Proposed Recommendation Recommendation
CCXML 1.0 Completed Completed 1Q2007 2Q2007 3Q2007 3Q2007
PLS 1.0 Completed Completed Completed 2Q2007 3Q2007 4Q2007
SISR 1.0 Completed Completed Completed 2Q2007 3Q2007 4Q2007
SSML 1.1 1Q2007 1Q2007 2Q2007 3Q2007 4Q2007 1Q2008
VoiceXML 2.1 Completed Completed Completed 11/2006 12/2006 1Q2007
VoiceXML 3.0 1Q2007 3Q2007 3Q2008 TBD TBD TBD
SCXML 1.0 1Q2007 Completed 3Q2007 1Q2008 3Q2008 3Q2008




These are related activities that the Group may need to interact with in ways to be determined, for example, to ask them to review this Group's draft specifications, and for this Group to take advantage of their work to fulfil its needs. Collaboration across working groups will be essential to realizing the mission of the Voice Browser Activity.

W3C-related activities

The following groups are identified as being related to the work of this group.

External groups

Here is a list of external groups with complementary goals to the Voice Browser activity:


To be successful, the Voice Browser Working Group is expected to have 15 or more active participants for its duration. Effective participation to Voice Browser Working Group is expected to consume one work day per week for each participant; two days per week for editors. The Voice Browser Working Group will allocate also the necessary resources for building Test Suites for each specification. In order to make rapid progress, the Voice Browser Working Group consists of several subgroups, each working on a separate document. Voice Browser Working Group members may participate in one or more subgroups.

Participants are reminded of the Good Standing requirements of the W3C Process.

To become a participant of the Working Group, a representative of a W3C Member organization must be nominated by their Advisory Committee Representative as described in the W3C Process. The associated IPR disclosure must further satisfy the requirements specified in the W3C Patent Policy (5 February 2004 Version).

Experts from appropriate communities may also be invited to join the working group, following the provisions for this in the W3C Process.

Working Group participants are not obligated to participate in every work item, however the Working Group as a whole is responsible for reviewing and accepting all work items.

Face to face meetings will be arranged 3 to 4 times a year. The Chair will make Working Group meeting dates and locations available to the group in a timely manner according to the W3C Process. The Chair is also responsible for providing publicly accessible summaries of Working Group face to face meetings, which will be announced on www-voice@w3.org.


This group primarily conducts its work on the Member-only mailing list w3c-voice-wg@w3.org (archive). Certain topics need coordination with external groups. The Chair and the Working Group can agree to discuss these topics on a public mailing list. The archived mailing list www-voice@w3.org is used for public discussion of W3C proposals for Voice Browsers and for public feedback on the group's deliverables.

Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the Voice Browser Working Group home page.

All proceedings of the Working Group (mail archives, telecon minutes, face-to-face minutes) will be available to W3C Members. Summaries of face-to-face meetings will be sent to the public list.

Decision Policy

As explained in the Process Document (section 3.3), this group will seek to make decisions when there is consensus. When the Chair puts a question and observes dissent, after due consideration of different opinions, the Chair should record a decision (possibly after a formal vote) and any objections, and move on.

This charter is written in accordance with Section 3.4, Votes of the W3C Process Document and includes no voting procedures beyond what the Process Document requires.

Patent Policy

This Working Group operates under the W3C Patent Policy (5 February 2004 Version). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis.

For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.

About this Charter

This charter for the Voice Browser Working Group has been created according to section 6.2 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

Please also see the previous charter for this group.

Note: This charter was modified on 26 November 2007 to included the informative note in section 4.1 referring readers to the home page of the group for updated milestone information.

James A. Larson, Co-chair, Voice Browser Working Group
Max Froumentin, Voice Browser Activity Lead
Kazuyuki Ashimura, Voice Browser Working Group staff contact

$Date: 2007/11/26 23:18:30 $