Speech-to-Text Continuous Recognition in C#

This page was automatically generated by AI; not yet reviewed for accuracy...

The content and code samples on this page were generated by using the ai CLI with customized prompts in this repository.

It's cool, but, it's experimental. 😁

Please review the content and code before using it in your application.

This sample demonstrates how to perform continuous speech recognition using the Speech SDK in a C# console application. The application listens for speech from the default microphone and prints recognized text to the console in real-time.

Program.cs

How to generate this sample

Command

ai dev new speech-to-text-continuous-reco --csharp

Output

AI - Azure AI CLI, Version 1.0.0
Copyright (c) 2024 Microsoft Corporation. All Rights Reserved.

This PUBLIC PREVIEW version may change at any time.
See: https://aka.ms/azure-ai-cli-public-preview

Generating 'speech-to-text-continuous-reco' in 'speech-to-text-continuous-reco-cs' (2 files)...

SpeechToTextContinuousReco.csproj
Program.cs

Generating 'speech-to-text-continuous-reco' in 'speech-to-text-continuous-reco-cs' (2 files)... DONE!

Program.cs

STEP 1: Read the configuration settings from environment variables:

Program.cs

var speechKey = Environment.GetEnvironmentVariable("AZURE_AI_SPEECH_KEY") ?? "<insert your Speech Service API key here>";
var speechRegion = Environment.GetEnvironmentVariable("AZURE_AI_SPEECH_REGION") ?? "<insert your Speech Service region here>";
var speechLanguage = "en-US"; // BCP-47 language code

STEP 2: Create instances of a speech config, source language config, and audio config:

Program.cs

var config = SpeechConfig.FromSubscription(speechKey, speechRegion);
var sourceLanguageConfig = SourceLanguageConfig.FromLanguage(speechLanguage);
var audioConfig = AudioConfig.FromDefaultMicrophoneInput();

STEP 3: Create the speech recognizer from the above configuration information:

Program.cs

using (var recognizer = new SpeechRecognizer(config, sourceLanguageConfig, audioConfig))
{
    recognizer.Recognizing += (s, e) => HandleRecognizingEvent(e);
    recognizer.Recognized += (s, e) => HandleRecognizedEvent(e);
    var sessionStoppedNoError = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);
    recognizer.SessionStarted += (s, e) => HandleSessionStartedEvent(e);
    recognizer.SessionStopped += (s, e) => HandleSessionStoppedEvent(e, sessionStoppedNoError);
    recognizer.Canceled += (s, e) => HandleCanceledEvent(e, sessionStoppedNoError);
    Task.Run(() =>
    {
        while (Console.ReadKey().Key != ConsoleKey.Enter) { }
        recognizer.StopContinuousRecognitionAsync();
    });
    await recognizer.StartContinuousRecognitionAsync();
    Console.WriteLine("Listening; press ENTER to stop ...\n");
    return await sessionStoppedNoError.Task ? 0 : 1;
}

STEP 4: Handle intermediate and final recognition results:

Program.cs

private static void HandleRecognizingEvent(SpeechRecognitionEventArgs e)
{
    Console.WriteLine($"RECOGNIZING: {e.Result.Text}");
}

private static void HandleRecognizedEvent(SpeechRecognitionEventArgs e)
{
    if (e.Result.Reason == ResultReason.RecognizedSpeech && !string.IsNullOrEmpty(e.Result.Text))
    {
        Console.WriteLine($"RECOGNIZED: {e.Result.Text}\n");
    }
    else if (e.Result.Reason == ResultReason.NoMatch)
    {
        Console.WriteLine($"NOMATCH: Speech could not be recognized.\n");
    }
}

STEP 5: Handle session start, stop, and cancellation events:

Program.cs

private static void HandleSessionStartedEvent(SessionEventArgs e)
{
    Console.WriteLine($"SESSION STARTED: {e.SessionId}.\n");
}

private static void HandleSessionStoppedEvent(SessionEventArgs e, TaskCompletionSource<bool> sessionStoppedNoError)
{
    Console.WriteLine($"SESSION STOPPED: {e.SessionId}.");
    sessionStoppedNoError.TrySetResult(true);
}

private static void HandleCanceledEvent(SpeechRecognitionCanceledEventArgs e, TaskCompletionSource<bool> sessionStoppedNoError)
{
    Console.WriteLine($"CANCELED: Reason={e.Reason}");
    if (e.Reason == CancellationReason.EndOfStream)
    {
        Console.WriteLine($"CANCELED: End of the audio stream was reached.");
    }
    else if (e.Reason == CancellationReason.Error)
    {
        Console.WriteLine($"CANCELED: ErrorCode={e.ErrorCode}");
        Console.WriteLine($"CANCELED: ErrorDetails={e.ErrorDetails}");
        Console.WriteLine($"CANCELED: Did you update the subscription info?");
    }
    sessionStoppedNoError.TrySetResult(e.Reason != CancellationReason.Error);
}