SpeechRecoContext Hypothesis Event (SAPI 5.4)
Interface: ISpeechRecoContext Events
The Hypothesis event occurs when the SR engine produces a hypothesis.
A hypothesis is an interim recognition result. Each time the engine attempts a recognition it generates an interim results and Hypothesis events are sent out. A hypothesis may or may not be close to the final version of the recognition. In fact, a hypothesis may not bear any likeness to the final result due to the sound quality, idiomatic phrasing, or uncommon word or phrase usage.
The member Result is a valid recognition result and may be used in the same way as a Recognition event. However, the values are interim and could change for the next Hypothesis event.
SpeechRecoContext.Hypothesis( StreamNumber As Long, StreamPosition As Variant, Result As ISpeechRecoResult )
- Specifies the stream number.
- Specifies the position within the stream.
- An ISpeechRecoResult object containing the recognition results.
The following Visual Basic form code demonstrates the use of the Hypothesis event. The application displays all the hypotheses for the current recognition attempt and then displays the final recognition.
To run this code, create a form with the following controls:
- Two labels called Label1 and Label2
Paste this code into the Declarations section of the form.
The Form_Load procedure creates and activates a dictation grammar. The PhraseStart event clears the display each time so the current hypothesis is displayed. For longer recognitions, a larger Label1 may be used or changed to a scrolling text box.
Public WithEvents RC As SpSharedRecoContext Public myGrammar As ISpeechRecoGrammar Private Sub Form_Load() Set RC = New SpSharedRecoContext Set myGrammar = RC.CreateGrammar myGrammar.DictationSetState SGDSActive End Sub Private Sub RC_Hypothesis(ByVal StreamNumber As Long, ByVal StreamPosition As Variant, ByVal Result As SpeechLib.ISpeechRecoResult) Label1.Caption = Label1.Caption & Result.PhraseInfo.GetText & vbCrLf End Sub Private Sub RC_PhraseStart(ByVal StreamNumber As Long, ByVal StreamPosition As Variant) Label1.Caption = "" End Sub Private Sub RC_Recognition(ByVal StreamNumber As Long, ByVal StreamPosition As Variant, ByVal RecognitionType As SpeechLib.SpeechRecognitionType, ByVal Result As SpeechLib.ISpeechRecoResult) Label2.Caption = Result.PhraseInfo.GetText End Sub