Speech 101, Part 2 - Using C# to Recognize “Hello World”

In my last post I covered how to perform basic speech recognition with a simple grammar and a “Hello World” WAV recording in C++. This post will cover how to accomplish what was in the previous post, but this time using the managed APIs.

Sound Check, Round 2

The support files for this example can be found here. Both HelloWorld.xml and HelloWorld.wav are required.

Again, in addition to the helper files the Windows SDK is also required.

Hello, Hello? Is this C#?

The most basic Speech recognition work flow is this:

1. Create a Speech Recognition Engine
2. Load a Grammar
3. Set the Engine’s input
4. Handle Recognition Events
5. Start Recognition

First, launch Visual Studio and create a new Visual C# Console Application. Copy the two helper files to the project root directory, add them to the project and set their properties to “Copy on Build”.

Next, it is time to create a SpeechRecognitionEngine and Grammar:

SpeechRecognitionEngine srEngine = new SpeechRecognitionEngine();

Grammar gram = new Grammar("helloworld.xml");

Now, load the grammar into the engine and set the engine’s input to the sample wave file:

srEngine.LoadGrammar(gram);
srEngine.SetInputToWaveFile("helloworld.wav");

Last thing to do is handle the recognition events and start recognition:

srEngine.SpeechRecognized += new EventHandler<SpeechRecognizedEventArgs>(srEngine_SpeechRecognized);
srEngine.Recognize();

Here’s an easy example for the Recognition Handler:

static void srEngine_SpeechRecognized(object sender, SpeechRecognizedEventArgs e)
{
Console.WriteLine("Detected: " + e.Result.Text);
}

That’s it. When the application runs, “Detected: Hello world” should be written to the console window.

Now you have a simple recognition example in just 10 lines of code.

What Next?

Try out some of the SAPI experiments listed in my first Speech 101 post. Also, look at the different recognition events and results. 

Resources

MSDN’s Documentation on the Speech Recognition Engine:
https://msdn.microsoft.com/en-us/library/hh361636.aspx

MSDN’s Starting Point for Speech Recognition:
https://msdn.microsoft.com/en-us/library/hh361633.aspx

Comments

• Anonymous
  February 02, 2012
  Thank you Robert for this article, I am going to test it. Regards !

• Anonymous
  February 03, 2012
  thaks

• Anonymous
  February 06, 2012
  really good

• Anonymous
  February 10, 2012
  Thanks a lot Robert, really helpful

• Anonymous
  February 11, 2012
  can i use it as a trigger event,for user imput  is that what you mean

• Anonymous
  February 14, 2012
  Muy bueno, haré mas pruebas!!!

• Anonymous
  February 21, 2012
  More insight for u. Tx

• Anonymous
  February 23, 2012
  Thanks for your visiting at www.sysnet.pe.kr/.../1228 Also, thanks to your post, I could write the article in Korean. :)

• Anonymous
  February 23, 2012
  cool story bro, tell it again

• Anonymous
  March 06, 2012
  can you give real time speach recoganization with code

• Anonymous
  March 07, 2012
  nice

• Anonymous
  March 14, 2012
  very good and useful

• Anonymous
  March 18, 2012
  nice one

• Anonymous
  March 29, 2012
  its useful

• Anonymous
  March 29, 2012
  Thanks - will try.  Short and sweet.

• Anonymous
  April 13, 2012
  are this program is applicable in visual studio 2008?

• Anonymous
  April 13, 2012
  @Prateek, Yes I believe that this will work within VS2008.  Just install the required dependencies and the latest versions of .NET.