How to Record Audio in .NET

Recording audio from a microphone in .NET or C# applications can be more challenging than it seems. Whether you're building voice-enabled apps, real-time speech-to-text, or accessibility features, capturing clear, high-quality audio in the correct format is crucial.

This guide explains how to record microphone audio in C# and .NET using PvRecorder: a lightweight, cross-platform .NET audio recording library that captures raw PCM audio frames for any speech recognition, voice command, or audio processing workflow.

Recording Audio in .NET with PvRecorder

Before we begin, make sure your system meets the minimum .NET version requirements for your platform:

• Windows (x86_64): .NET Framework 4.6.1+, .NET Standard 2.0+, or .NET Core 3.0+
• macOS (x86_64): .NET Standard 2.0+ or .NET Core 3.0+
• macOS (arm64), Windows (arm64), Linux (x86_64), Raspberry Pi (3, 4, 5): .NET 6.0+

1. Install the NuGet Package

Install the PvRecorder NuGet package:

dotnet add package PvRecorder

2. Initialize PvRecorder

Pass in the required frame length for your processing engine or logic. Picovoice engines typically require a frame length of 512:

PvRecorder recorder = PvRecorder.Create(frameLength: 512);

3. Start Audio Capture

Call Start() to begin recording audio:

recorder.Start();

4. Capture PCM Audio Frames

After starting the recorder, continuously read audio frames inside a loop:

while (recorder.IsRecording)
{
    short[] audioFrame = recorder.Read();
    // process audio: e.g. engine.process(audioFrame);
}

Each frame is a short[] array containing raw 16-bit PCM samples that you can feed into your audio processing logic, speech recognizer, or write to a file.

5. Stop & Release Resources

To stop recording audio, call Stop(). If you no longer need PvRecorder, call Dispose() to free memory:

recorder.Stop();
recorder.Dispose();

Complete .NET Audio Recording Example

Here's a complete .NET console example that records audio from the default microphone, prints the frame length read, and stops on Enter.

using System;
using System.Threading;
using Pv;

class Program
{
    static void Main()
    {
        Console.WriteLine("Initializing PvRecorder...");
        PvRecorder recorder = PvRecorder.Create(frameLength: 512);

        var processingThread = new Thread(() =>
        {
            while (recorder.IsRecording)
            {
                // Your processing logic here.
                short[] audioFrame = recorder.Read();
                Console.WriteLine($"Read {audioFrame.Length} samples.");
            }
        });

        recorder.Start();
        processingThread.Start();

        Console.WriteLine("Recording started. Press Enter to stop.");
        Console.ReadLine();

        recorder.Stop();
        processingThread.Join();

        recorder.Dispose();
        Console.WriteLine("Stopped and resources released.");
    }
}

This is a simplified example but contains all the essential components to demonstrate audio recording functionality. If you'd like to see a complete working project, check out the PvRecorder .NET Demo on GitHub.

This tutorial uses the following package:

• PvRecorder NuGet Package

Explore our documentation for more details:

• PvRecorder .NET Quick Start
• PvRecorder .NET API

Next Steps

Now that you know how to record audio, you can add the speech recognition features your .NET application needs:

• Porcupine Wake Word: custom wake words so your app can "wake up" to a configured phrase.
• Rhino Speech-to-Intent: custom voice commands so your app can understand what a user is saying, and perform appropriate response.
• Cheetah Streaming Speech-to-Text: real-time transcription so your app can transcribe speech in real time.

Frequently Asked Questions