Speech Objects

The WTE uses a TTS engine to render HTML content to a telephone caller and, optionally, an SR engine to gather spoken input from the caller. To communicate with a TTS or SR engine, the WTE uses the Microsoft Speech Application Programming Interface (SAPI) 4.0a. For this reason, any SAPI-compliant TTS or SR engine can be used. The WTE can use the Microsoft TTS Engine included with Windows 2000, and the Microsoft SR Engine, if it is installed on the computer. The Microsoft SR Engine must be installed from the SAPI 4.0a Software Developer's Kit (SDK)—it is not installed by default. For more information about SAPI, see the MSDN library.

The mode information maintained by the TTS and SR engines is exposed to a Web telephony application through the TTSMode and SRMode objects of the extended object model. These objects provide read-only access. In addition, the WTEApplication object provides read-write access to several speech-related configuration parameters for an application.