Using SAPI 5 to Convert Text to WAV file

Here is AutoIt Script sample script:

#Region ;**** Directives created by AutoIt3Wrapper_GUI ****
#AutoIt3Wrapper_Icon=tango-icon-theme-0.8.1\16x16\actions\media-record.ico
#EndRegion ;**** Directives created by AutoIt3Wrapper_GUI ****
;    http://tango.freedesktop.org/Icon_Metaphors
Dim $i
Func ConvertTextToWAV($asFN)
    Dim $text, $oSPV, $oSPSTRM, $WAV
    $oSPV = ObjCreate('SAPI.SpVoice')
    $oSPSTRM = ObjCreate('SAPI.SpFileStream')
    $text = FileRead($asFN)
    $WAV = StringReplace($asFN, '.txt', '.wav')
    If FileExists($WAV) Then FileDelete($WAV)
    $oSPSTRM.Open($WAV, 3, False)
    $oSPV.AudioOutputStream = $oSPSTRM
    $oSPV.Speak($text)
    $oSPSTRM.Close
EndFunc   ;==>TextToWAV
For $i = 1 To $cmdline[0]
    ConvertTextToWAV($cmdline[$i])
Next

NOTE: To use drag .txt files atop  
compiled version of the script.