private void button2_Click(object sender, EventArgs e)
        {
            if (sourceList.SelectedItems.Count == 0) return;

            int deviceNumber = sourceList.SelectedItems[0].Index;
            sourceStream = new WaveIn();
            sourceStream.DeviceNumber = deviceNumber;
            sourceStream.WaveFormat = new WaveFormat(44100, WaveIn.GetCapabilities(deviceNumber).Channels);
            sourceStream.StartRecording();

            WaveInProvider waveIn = new WaveInProvider(sourceStream);

            waveOut = new DirectSoundOut();
            waveOut.Init(waveIn);
            waveOut.Play();
        }