Grammar

Posted February 26th, 2010 by victor
in

Grammars are used by speech recognizers to determine what the recognizer should listen for, and so describe the utterances a user may say. Starting with VoiceXML Version 2.0, the W3C requires that all VoiceXML platforms must support at least one common format, the XML Form of the W3C Speech Recognition Grammar Specification (SRGS). Plum implements the SRGS+XML grammar format for both Voice and DTMF grammars as well as JSpeech Grammar Format (JSGF). Refer to the W3C Speech Recognition Grammar Specification or the JSGF Specification for further detail.

In order to use SRGS grammars (sometimes referred to as ABNF), the type must be explicitly set within each grammar tag. To explicitly specify an SRGS+XML grammar, set the "type" attribute of the grammar tag to "application/srgs+xml". Please also keep in mind that when you specify an SRGS+XML grammar, it is required that you include a root attribute.

The JSpeech Grammar Format (JSGF) is a platform-independent, vendor-independent textual representation of grammars for use in speech recognition. JSGF adopts the style and conventions of the Java™ Programming Language in addition to the use of traditional grammar notations. The JSGF grammar syntax is the default syntax for the Plum Voice Platform. JSGF can be used to specify speech and DTMF grammars. Refer to the JSGF Specification for further detail.

Since JSGF is not a part of the VoiceXML 2.0 specification, the integration of JSGF into the Plum Voice Platform has been based upon the VoiceXML 1.0 specification. JSGF is considered the default grammar type. To explicitly specify a JSGF grammar, set the "type" attribute of the grammar tag to "application/x-jsgf".

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