Note
Please see Azure Cognitive Services for Speech documentation for the latest supported speech solutions.
RecognizedWordUnit.Confidence Property
Gets a value, assigned by the recognizer, that represents the likelihood that a recognized word matches a given input.
Namespace: Microsoft.Speech.Recognition
Assembly: Microsoft.Speech (in Microsoft.Speech.dll)
Syntax
'Declaration
Public ReadOnly Property Confidence As Single
Get
'Usage
Dim instance As RecognizedWordUnit
Dim value As Single
value = instance.Confidence
public float Confidence { get; }
Property Value
Type: System.Single
Returns a float, typically between 0 and 1, indicating the certainty of the speech recognition engine as to the correctness of recognition for a word.
Remarks
Confidence scores do not indicate the absolute likelihood that a word was recognized correctly. Instead, confidence scores provide a mechanism for comparing the relative accuracy of multiple recognition alternates for a given input. This facilitates returning the most accurate recognition result. For example, if a recognized word has a confidence score of 0.8, this does not mean that the word has an 80% chance of being the correct match for the input. It means that the word is more likely to be the correct match for the input than other results that have confidence scores less than 0.8.
A confidence score on its own is not meaningful unless you have alternative results to compare against, either from the same recognition operation or from previous recognitions of the same input.
The values returned by Confidence are relative and unique to each recognition engine. There is no definition of how confidence values between two different recognition engines compare, nor how the Confidence of individual RecognizedWordUnit objects define the Confidence of a RecognizedPhrase.
A speech recognition engine may assign a low confidence score to spoken input for various reasons, including background interference, inarticulate speech, or unanticipated words or word sequences. If your application is using a SpeechRecognitionEngine instance, you can modify the confidence level at which speech input is accepted or rejected with one of the UpdateRecognizerSetting() methods.