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.

Join the Voice Browser Working Group.

End date 31 August 2015
Confidentiality Proceedings are Member-only, but the group sends regular summaries of ongoing work to the public mailing list.
Initial Chairs Daniel Burnett
Initial Team Contacts
(FTE %: 20)
Kazuyuki Ashimura
Usual Meeting Schedule Teleconferences: Weekly
  • The group plans to hold separate telephone conferences for the following Task Force as well as the main group:
    • SCXML 1.0
Face-to-face: as required up to 3 per year



The Voice Browser Working Group's mission is to support browsing the web by voice. The web is much more than just the web pages you can see, it is also the web pages you can hear and speak to. While end users are familiar with interacting with visual html web pages rendered in their browser of choice, many users might be surprised to realize that today they regularly interact with the voice web through VoiceXML (VXML) and other technologies developed and standardized by the Voice Browser Working Group. Just as many sites have an HTML presence on the web for visual browsing, most large companies have a VXML presence on the web for voice browsing, which is most often accessed by calling the company's phone number. Unlike most visual web browsers, voice web browsers are typically without chrome and run in the cloud, so they are often transparent to the end user. But otherwise, all the normal power of the web applies including taking advantage of web services, markup, linking, URIs, caching, standards, accessibility, and cross-browser support. The W3C Speech Interface Framework is a suite of independent standards that are also supported as parts of VoiceXML. These standards can be, and are being, used alone in non-VXML contexts; however, they achieve a powerful synergy when used in support of VXML.

Applications using these standards today include:

  • Accessing business information, including the corporate "front desk" asking callers who or what they want, automated telephone ordering services, support desks, order tracking, airline arrival and departure information, cinema and theater booking services, and home banking services such as transferring money from one account to another, purchasing an item, trading stock.
  • Accessing public information, including community information such as weather, traffic conditions, school closures, directions and events; local, national and international news; national and international stock market information; and business and e-commerce transactions.
  • Accessing personal information, including calendars, address and telephone lists, to-do lists, shopping lists, and calorie counters.
  • Assisting the user to communicate with other people via sending and receiving voice-mail and email messages.

Work to do

State Chart XML (SCXML) 1.0

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 of other types of applications. The Group plans to take SCXML 1.0 through to Recommendation status.

Maintenance work

The Working Group will be maintaining its existing Recommendations: VoiceXML 2.0/2.1, SRGS 1.0, SSML 1.0/1.1, SISR 1.0, PLS 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

For the target document to advance to Recommendation, the group will typically produce a technical report with two independent and interoperable implementations for each required feature. The working group anticipates two interoperable implementations for each optional feature but may reduce the criteria for specific optional features.


The following document is expected to become a W3C Recommendation:

Note: The group focuses on SCXML 1.0 for the extended charter period until 31 October 2014.


Note: See changes from this initial schedule on the group home page.
Specification Requirements FPWD LC CR PR Rec
SCXML 1.0 Completed Completed Completed Completed Q2 2014 Q3 2014


W3C Groups

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

The specifications of the VBWG are expected to be usable worldwide and be adapted to a wide variety all language. An ongoing strong relationship with the I18N groups is essential to achieve this goal.
Multimodal Interaction WG
The MMIWG has a strong link to the VBWG as it is chartered to develop specifications that allow to use the Web with using any modality, not just voice.
WAI Protocols and Formats WG
The VBWG expects that its work will be reviewed by the WAI-PF group, in order to ensure universal accessibility of the produced specifications.
Speech API CG
The HTML Speech Incubator Group wrapped up in December 2011. There is currently a new Speech Community Group that is discussing a subset of the JavaScript API work. Additionally, we expect that there will be a Recommendation-track working group within W3C and/or other Standards Development Organizations such as the Internet Engineering Task Force. Because this work is in a similar technical domain to some of the work in the Voice Browser Working Group, the VBWG will correspond with these other working groups as necessary.
The WebRTC effort is focused on enabling browser-to-browser communications. Since the world is rapidly moving to mobile devices whose primary interfaces are browsers, it is likely that voice communications will increasingly occur over the data channel on mobile devices. As a consequence, such communications may well end up terminating in Voice Browsers. The Voice Browser Working Group will monitor this effort to ensure that communications intended to run in Voice Browsers will work as expected over this "new" voice network.
Audio WG
The Audio Working Group is interested in a variety of ways in which audio can be manipulated from within HTML. One manipulation of interest is the generation of speech audio from text, an area in which the Voice Browser Working Group has both significant experience and established Recommendations. The Voice Browser Working Group stands ready to review and assist with any efforts in this direction that the Audio Working Group may undertake.

Furthermore, Voice Browser Working Group expects to follow these W3C Recommendations:

External Groups

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

works on DSR codecs, call control, human factors and command vocabularies.
prepares an update to the Language Subtag Registry procedures and deliver means to update the current IANA Language Subtag Registry.
IETF SPEECHSC working group or its successor
works on protocols for accessing speech engines. Develops MRCPv2 and any successor.
IETF Media Control
works on protocols and XML languages for media servers.
works on call control and media control API's inside java.
VoiceXML Forum

A memorandum of understanding exists between W3C and the VoiceXML Forum which basically states that:

  • The W3C will define dialog markup languages while the Forum concentrates on conformance, education, and marketing.
  • The VoiceXML Forum will coordinate the creation of test suites and conformance evaluation with the W3C.
  • The VoiceXML Forum will provide specification clarification requests to the W3C through the channels provided by the W3C for this purpose.

The VBWG will continue to respect this arrangement and furthermore plans to hold regularly scheduled joint meetings to coordinate conformance issues and other activities.


To be successful, the Voice Browser Working Group is expected to have 5 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. The Voice Browser Working Group members may participate in one or more subgroups.

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

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.

For budgeting purposes, the group may hold up to three full working group face-to-face meetings per year if the group believe it to be beneficial. Currently the Working Group anticipate holding a face-to-face meeting in association with the Technical Plenary but have no additional face-to-face meetings planned. 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, teleconference 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.

The most important changes from the previous charter are:

This charter was updated with the following change in August 2012:

This charter was updated with the following changes in April 2014:

This charter was updated with the following change on 16 December 2014:

This charter was updated with the following change on 9 June 2015:

Daniel C. Burnett, Chair, Voice Browser Working Group
Kazuyuki Ashimura, Voice Browser Activity Lead

$Date: 2015/06/10 03:15:25 $