public static extern int waveInUnprepareHeader(IntPtr hwi, ref tWAVEHDR pwh, int cbwh);
public static extern int waveOutWrite(IntPtr hwo, ref tWAVEHDR pwh, int cbwh);
public static extern int waveInAddBuffer(IntPtr hwi, ref tWAVEHDR pwh, int cbwh);
public static extern int waveOutPrepareHeader(IntPtr hwo, ref tWAVEHDR pwh, int cbwh);