/// <summary>
        /// Plays test audio.
        /// </summary>
        private void PlayTestAudio()
        {
            try{
                using (FileStream fs = File.OpenRead(m_PlayFile)){
                    byte[] buffer       = new byte[400];
                    int    readedCount  = fs.Read(buffer, 0, buffer.Length);
                    long   lastSendTime = DateTime.Now.Ticks;
                    while (m_IsSendingTest && readedCount > 0)
                    {
                        // Send and read next.
                        m_pWaveOut.Write(buffer, 0, readedCount);
                        readedCount = fs.Read(buffer, 0, buffer.Length);

                        Thread.Sleep(25);

                        lastSendTime = DateTime.Now.Ticks;
                    }
                }
            }
            catch (Exception x) {
                MessageBox.Show(null, "Error: " + x.ToString(), "Error:", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }