When you try to run a Microsoft speech-based application in Windows Vista, the application may not work. Additionally, you may receive an error message that resembles one of the following error messages.
Error message 1
An error occurred when creating or initializing the recognition context, so speech recognition will not work.
Error message 2
This voice cannot be played. Please try selecting another voice or selecting a different audio output device
This issue may occur when the application uses Microsoft Speech API (SAPI) 5.1 speech recognition (SR) engines or when the application uses the SAPI 5.1 Test to Speech (TTS) engines.
Note This issue does not occur on a Windows XP-based computer.
This issue occurs because Windows Vista does not have the Spcommon.dll component on which SAPI 5.1 engines rely. Therefore, you cannot run an application that relies on SAPI 5.1 engines in Windows Vista.
This behavior is by design.
When you run an application that uses SAPI engines, the application will search for the speech recognition (SR) engines in the system. In Windows Vista, the default SR engine is the Microsoft Speech Recognizer 8.0 for Windows SR engine. In most cases, the application works correctly with the default Windows Vista SR engine.
However, a SAPI-based application may have to use the SR engine of a special language version that differs from the language version of the operating system. In this scenario, the SAPI-based application will search for an earlier version of the SR engine, according to the language version of the operating system.
If the application finally uses the Microsoft Speech Recognizer v5.1 SR engine, the application will not work because this SR engine does not run in Windows Vista.
Note SR engines are included in the Windows Multilingual User Interface Pack (MUI) in Windows Vista. This means that the language version for the SR engines depends on the Windows MUI that is installed in Windows Vista.
For more information about SAPI, visit the following Microsoft Web site: