Quickstart: Recognize speech with the Speech SDK for .NET Framework (Windows)

Quickstarts are also available for text-to-speech and speech-translation.

If desired, choose a different programming language and/or environment:

Use this guide to create a speech-to-text console application using the .NET framework for Windows and the Speech SDK. When finished, you can use your computer's microphone to transcribe speech to text in real time.

For a quick demonstration (without building the Visual Studio project yourself as shown below):

Get the latest Cognitive Services Speech SDK Samples from GitHub.


To complete this project, you'll need:

Create a Visual Studio project

  1. Start Visual Studio 2017.

  2. From the menu bar in Visual Studio, select Tools > Get Tools and make sure that the .NET desktop development workload is available. If the workload hasn't been installed, mark the checkbox, then click Modify to start the installation. It may take a few minutes to download and install.

    If the checkbox next to .NET desktop development is selected, you can close the dialog box now.

    Enable .NET desktop development

  3. Next, let's create a project. From the menu bar select File > New > Project. When the dialog box appears, from the left panel expand these sections Installed > Visual C# > Windows Desktop and select Console App (.NET Framework). Name this project helloworld.

    Create Visual C# Console App (.NET Framework)

  4. Now that the project is set up, we need to install the Speech SDK NuGet package and reference it in our code. Locate the Solution Explorer and right-click on helloworld. From the menu, select Manage NuGet Packages....

    Right-click Manage NuGet Packages for Solution

  5. In the upper-right corner of the NuGet Package Manager, locate the Package Source dropdown and make sure that nuget.org is selected. Then, select Browse and search for the Microsoft.CognitiveServices.Speech package and install the latest stable version.

    Install Microsoft.CognitiveServices.Speech NuGet Package

  6. Accept all agreements and licenses to start the installation.

    Accept the license

    After the package is installed, a confirmation appears in the Package Manager console.

  7. The next step is to create a platform configuration that matches the architecture of the computer you're using to build and run the console application. From the menu bar, select Build > Configuration Manager....

    Launch the configuration manager

  8. In the Configuration Manager dialog box, locate the Active solution platform drop-down list, and select New.

    Add a new platform under the configuration manager window

  9. If you are running 64-bit Windows, when prompted with Type or select the new platform, x64. If you are running 32-bit Windows, select x86. When you're finished, click OK.

    On 64-bit Windows, add a new platform named "x64"

Add sample code

  1. Open Program.cs and replace the automatically generated code with this sample:

    using System;
    using System.Threading.Tasks;
    using Microsoft.CognitiveServices.Speech;
    namespace helloworld
        class Program
            public static async Task RecognizeSpeechAsync()
                // Creates an instance of a speech config with specified subscription key and service region.
                // Replace with your own subscription key and service region (e.g., "westus").
                var config = SpeechConfig.FromSubscription("YourSubscriptionKey", "YourServiceRegion");
                // Creates a speech recognizer.
                using (var recognizer = new SpeechRecognizer(config))
                    Console.WriteLine("Say something...");
                    // Starts speech recognition, and returns after a single utterance is recognized. The end of a
                    // single utterance is determined by listening for silence at the end or until a maximum of 15
                    // seconds of audio is processed.  The task returns the recognition text as result. 
                    // Note: Since RecognizeOnceAsync() returns only a single utterance, it is suitable only for single
                    // shot recognition like command or query. 
                    // For long-running multi-utterance recognition, use StartContinuousRecognitionAsync() instead.
                    var result = await recognizer.RecognizeOnceAsync();
                    // Checks result.
                    if (result.Reason == ResultReason.RecognizedSpeech)
                        Console.WriteLine($"We recognized: {result.Text}");
                    else if (result.Reason == ResultReason.NoMatch)
                        Console.WriteLine($"NOMATCH: Speech could not be recognized.");
                    else if (result.Reason == ResultReason.Canceled)
                        var cancellation = CancellationDetails.FromResult(result);
                        Console.WriteLine($"CANCELED: Reason={cancellation.Reason}");
                        if (cancellation.Reason == CancellationReason.Error)
                            Console.WriteLine($"CANCELED: ErrorCode={cancellation.ErrorCode}");
                            Console.WriteLine($"CANCELED: ErrorDetails={cancellation.ErrorDetails}");
                            Console.WriteLine($"CANCELED: Did you update the subscription info?");
            static void Main()
                Console.WriteLine("Please press a key to continue.");
  2. Locate and replace the string YourSubscriptionKey with your Speech Services subscription key.

  3. Locate and replace the string YourServiceRegion with the region associated with your subscription. For example, if you're using the free trial, the region is westus.

  4. Save the changes to the project.

Build and run the app

  1. From the menu bar, select Build > Build Solution. The code should compile without errors now.

    Screenshot of Visual Studio application, with Build Solution option highlighted

  2. From the menu bar, select Debug > Start Debugging, or press F5 to start the application.

    Screenshot of Visual Studio application, with Start Debugging option highlighted

  3. A console window will appear, prompting you to speak. Now, say something in English. Your speech is transmitted to the Speech Services and transcribed to text in real time. The result is printed to the console.

    Screenshot of console output after successful recognition

Next steps

See also