New Post: Modify current audio output stream (add effect)

This is what I have so far, but it's only causing some sort of noise. I also don't see a way to control how often "DataAvailable" is called. I would rather like to record like 100ms and then play it at half volume to create the echo effect.

WasapiLoopbackCapture waveIn = new WasapiLoopbackCapture();
waveIn.DataAvailable += delegate(object sender, WaveInEventArgs e)
{
    try
    {
        byte[] bytes;
        using (MemoryStream mem = new MemoryStream())
        {
            using (WaveFileWriter file = new WaveFileWriter(mem, new WaveFormat(44000, 2)))
            {
                file.Write(e.Buffer, 0, e.BytesRecorded);
            }
            bytes = mem.ToArray();
        }
        WaveOut waveOut = new WaveOut();
        waveOut.Init(new WaveFileReader(new MemoryStream(bytes)));
        waveOut.Play();
    }
    catch (Exception ex)
    {

    }
};
waveIn.StartRecording();
Application.Run();