Limitations When Using a TIM

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Using a Telephony Interface Manager (TIM) on a computer running Speech Server imposes the following programmatic limitations:

• The BookmarkReached event cannot be raised.
• The SpeakCompleted event cannot send an accurate time Offset value.
• The ToneDetected event cannot send accurate values for Duration and Volume.
• The Skip method does not work as expected.
• The SetSelectedOptionToMostRecentBookmark method does not work as expected when debugging applications using the default grammar of the MenuActivity object.

These limitations can adversely affect applications that, for example:

• Subscribe to the ISynthesizer.BookmarkReached event to associate a bookmark with a specific item when the event is raised.
• Use the ISynthesizer.Skip method to enable users to skip forwards or backwards within the prompt by a specified amount of time.
• Use the value of the SpeakCompletedEventArgs.Offset property to determine how much of a prompt is played before the SpeakCompleted event is raised.
• Use the value of the ToneDetectedEventArgs.Duration or ToneDetectedEventArgs.Volume property to validate the detection of DTMF tones.
• Use the ISynthesizer.Skip method to enable users to skip playing the remainder of a partially played prompt.

MenuActivity Object Behavior

Using a TIM on a computer running Speech Server can also affect the default behavior of MenuActivity objects.

When a MenuActivity object runs, it plays a list of menu options that are drawn from a data source. For the purpose of debugging, the Speech Server API provides a default grammar for MenuActivity that includes a "that one" command. Using the default grammar, when the user says "that one" while the MenuActivity object plays a menu option, the object uses the BookmarkReached event to determine which menu option the user selected. However, on computers running a TIM, because the BookmarkReached event cannot be raised, saying "that one" while the MenuActivity object plays a menu option causes MenuActivity to throw an exception and stop the workflow, thus stopping the application.

To avoid issues with using MenuActivity while debugging applications on computers that use a TIM, set the UseDefaultGrammars property to False and avoid calling the MenuActivity.SetSelectedOptionToMostRecentBookmark method.