SpVoice Sentence event (SAPI 5.3)

Speech API 5.3
Microsoft Speech API 5.3

Object: SpVoice (Events)

Sentence Event

The Sentence event when the text-to-speech (TTS) engine detects a sentence boundary while speaking a stream for the SpVoice object.

     StreamNumber As Long,
     StreamPosition As Variant,
     CharacterPosition As Long,
     Length As Long


The stream number which generated the event. When a voice enqueues more than one stream by speaking asynchronously, the stream number is necessary to associate an event with the appropriate stream.
The character position in the output stream at which the sentence begins.
The character position in the input stream one character before the start of the sentence. In the case of the first sentence in a stream, this parameter is zero.
The length of the sentence.


The following Visual Basic form code demonstrates the use of the Sentence event. To run this code, create a form with the following controls:

  • A command button called Command1
  • A text box called Text1
  • Set the HideSelection property of Text1 to False

Paste this code into the Declarations section of the form.

The Form_Load procedure puts a text string in Text1 and creates a voice object. The command1_Click procedure calls the Speak method. This will cause the TTS engine to send the Sentence event to the voice. The Sentence event code uses the event parameters to highlight the sentence associated with the event.

Option Explicit

Public WithEvents vox As SpeechLib.SpVoice

Private Sub Command1_Click()

    vox.Speak Text1.Text, SVSFlagsAsync

End Sub

Private Sub Form_Load()

    Set vox = New SpVoice
    Text1.Text = "a short sentence. another sentence. one more."

End Sub

Private Sub vox_Sentence(ByVal StreamNumber As Long, ByVal StreamPosition As Variant, _
                         ByVal CharacterPosition As Long, ByVal Length As Long)

    ' In order to show this selection,
    ' the Text1.HideSelection property must be False

    Text1.SelStart = CharacterPosition
    Text1.SelLength = Length

End Sub