SpVoice AudioOutput property (SAPI 5.3)

Microsoft Speech API 5.3

Object: SpVoice

AudioOutput Property

The AudioOutput property gets and sets the current audio output object used by the voice.

The AudioOutput property can be set with the object token for a standard Windows multi-media device. To use other types of devices, please see the Speech Telephony Application Guide.


Set: SpVoice.AudioOutput = SpObjectToken
Get: SpObjectToken = SpVoice.AudioOutput


  • SpVoice
    The owning object.
  • SpObjectToken
    Get: An SpObjectToken object that gets the current audio output.
    Set: An SpObjectToken object that sets the audio output.


When setting the value, if the object is Nothing then the default audio device will be used.


The following Visual Basic form code demonstrates the use of the GetAudioOutputs method and the AudioOutput property. To run this code, create a form with the following controls:

  • A command button called Command1
  • A list box called List1

Paste this code into the Declarations section of the form.

The Form_Load procedure creates an SpVoice object and calls a subroutine called ShowAudioOutputs. This subroutine uses the GetAudioOutputs method to select all available output devices, and adds each device to the list box. The string (CURRENT) is appended to the current audio device name.

Select a device in the list box, and then click Command1. The Command1_Click procedure resets the voice's AudioOutput property to the device selected in the list box, and calls the ShowAudioOutputs subroutine, which will display the device selected as the current audio output.

Note If the computer currently has only one audio output device, clicking Command1 will not change the entry in the list box.

Option Explicit

Private V As SpeechLib.SpVoice
Private T As SpeechLib.SpObjectToken

Private Sub Form_Load()
    On Error GoTo EH
    Set V = New SpVoice
    Call ShowAudioOutputs

    If Err.Number Then ShowErrMsg
End Sub

Private Sub Command1_Click()
    On Error GoTo EH

    If List1.ListIndex > -1 Then
        Set V.AudioOutput = V.GetAudioOutputs().Item(List1.ListIndex)
        Call ShowAudioOutputs
    End If

    If Err.Number Then ShowErrMsg
End Sub

Private Sub ShowAudioOutputs()
    On Error GoTo EH

    Dim strAudio As String
    Dim strCurrentAudio As String

    Set T = V.AudioOutput               'Token for current audio output
    strCurrentAudio = T.GetDescription  'Get description from token

    'Show all available outputs; highlight the one in use

    For Each T In V.GetAudioOutputs
        strAudio = T.GetDescription     'Get description from token
        If strAudio = strCurrentAudio Then
            strAudio = strAudio & " (CURRENT)"  'Show current device
        End If
        List1.AddItem strAudio          'Add description to list box

    If Err.Number Then ShowErrMsg
End Sub

Private Sub ShowErrMsg()

    ' Declare identifiers:
    Dim T As String

    T = "Desc: " & Err.Description & vbNewLine
    T = T & "Err #: " & Err.Number
    MsgBox T, vbExclamation, "Run-Time Error"

End Sub