Speech recognition

# Inigo Surguy (inigosurguy at hotmail.com)
# Sample code for speech recognition using the MS Speech API
from win32com.client import constants
import win32com.client
import pythoncom

"""Sample code for using the Microsoft Speech SDK 5.1 via COM in Python.
    Requires that the SDK be installed (it's a free download from
    and that MakePy has been used on it (in PythonWin,
    select Tools | COM MakePy Utility | Microsoft Speech Object Library 5.1).

    After running this, then saying "One", "Two", "Three" or "Four" should
    display "You said One" etc on the console. The recognition can be a bit
    shaky at first until you've trained it (via the Speech entry in the Windows
    Control Panel."""

class SpeechRecognition:
    """ Initialize the speech recognition with the passed in list of words """
    def __init__(self, wordsToAdd):
        # For text-to-speech
        self.speaker = win32com.client.Dispatch("SAPI.SpVoice")
        # For speech recognition - first create a listener
        self.listener = win32com.client.Dispatch("SAPI.SpSharedRecognizer")
        # Then a recognition context
        self.context = self.listener.CreateRecoContext()
        # which has an associated grammar
        self.grammar = self.context.CreateGrammar()
        # Do not allow free word recognition - only command and control
        # recognizing the words in the grammar only
        # Create a new rule for the grammar, that is top level (so it begins
        # a recognition) and dynamic (ie we can change it at runtime)
        self.wordsRule = self.grammar.Rules.Add("wordsRule",
                        constants.SRATopLevel + constants.SRADynamic, 0)
        # Clear the rule (not necessary first time, but if we're changing it
        # dynamically then it's useful)
        # And go through the list of words, adding each to the rule
        [ self.wordsRule.InitialState.AddWordTransition(None, word) for word in wordsToAdd ]
        # Set the wordsRule to be active
        self.grammar.CmdSetRuleState("wordsRule", 1)
        # Commit the changes to the grammar
        # And add an event handler that's called back when recognition occurs
        self.eventHandler = ContextEvents(self.context)
        # Announce we've started
        self.say("Started successfully")
    """Speak a word or phrase"""
    def say(self, phrase):

"""The callback class that handles the events raised by the speech object.
    See "Automation | SpSharedRecoContext (Events)" in the MS Speech SDK
    online help for documentation of the other events supported. """
class ContextEvents(win32com.client.getevents("SAPI.SpSharedRecoContext")):
    """Called when a word/phrase is successfully recognized  -
        ie it is found in a currently open grammar with a sufficiently high
    def OnRecognition(self, StreamNumber, StreamPosition, RecognitionType, Result):
        newResult = win32com.client.Dispatch(Result)
        print "You said: ",newResult.PhraseInfo.GetText()
if __name__=='__main__':
    wordsToAdd = [ "One", "Two", "Three", "Four" ]
    speechReco = SpeechRecognition(wordsToAdd)
    while 1:

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.