| Element | Description | Implementation details |
|---|---|---|
| <audio> | Plays an audio file within a prompt or synthesizes speech from a text string if the audio file cannot be found. | Supported as documented in VoiceXML 2.0, except that the <audio> element cannot be contained within other SSML elements, such as in:<emphasis level=“strong”> <audio .../> </emphasis> |
| <break> | Inserts a pause in TTS output. | Supported as documented in VoiceXML 2.1. |
| <desc> | Describes the content of an audio source. | Supported as documented in VoiceXML 2.0. |
| <emphasis> | Specifies the emphasis for TTS output. | Supported as documented in VoiceXML 2.0. |
| <lexicon> | References external pronunciation definitions. | This element is not supported in Blueworx Voice Response. |
| <mark> | Inserts a reference point in a document. | This element is not supported in VoiceXML 2.0, but is supported in VoiceXML 2.1 as documented. |
| <metadata> | Specifies general information about the document. | This element is ignored by the VoiceXML browser. |
| <p> | Specifies text structure in the absence of an end of sentence punctuation character. | Supported as documented in VoiceXML 2.1. |
| <paragraph> | Specifies text structure in the absence of an end of sentence punctuation character. | Supported as documented in VoiceXML 2.0. |
| <phoneme> | Specifies the pronunciation and phonology for a TTS output. | Supported as documented in VoiceXML 2.0. |
| <prosody> | Controls the pitch, range, rate and volume of TTS output. | The contour and duration attributes are not supported. |
| <say-as> | Specifies the type of text. For example, date, telephone number or currency. | The following attribute values are not supported:
Note: The details=“punctuation” attribute value is not
supported in Simplified Chinese.
<say-as> can be
used with built-in grammar types. |
| <s> | Specifies text structure in the absence of an end of sentence punctuation character. | Supported as documented in VoiceXML 2.1. |
| <sentence> | Specifies text structure in the absence of an end of sentence punctuation character. | Supported as documented in VoiceXML 2.0. |
| <sub> | Specifies substitute text for TTS output in place of a given input string. | Supported as documented in VoiceXML 2.0. |
| <voice> | Specifies the speaking voice used for TTS ouput. | Supported as documented in VoiceXML 2.0. |
Language specific limitations and considerations are given in the language appendixes.