/// <summary>
        /// Logs the recognition start.
        /// </summary>
        private void LogRecognitionStart()
        {
            string recoSource;

            recoSource = this.UseMicrophone ? "microphone" : "wav file";

            RecognitionStartEventArgs eventArgs = new RecognitionStartEventArgs();

            eventArgs.Message = "--- Start speech recognition using " + recoSource + " in " + defaultLocale + " language ----";
            OnRecognitionStartEvent(eventArgs);
        }
 /// <summary>
 /// 認識スタートイベントを発生
 /// </summary>
 /// <param name="e"></param>
 protected virtual void OnRecognitionStartEvent(RecognitionStartEventArgs e)
 {
     RecognitionStartEvent?.Invoke(this, e);
 }