Android语音识别器。如何播放“就绪”声音事件?

speechRecognizer.startListening(speechIntent) 

有时需要很长时间才能播放“就绪”声音(大部分是在应用程序重新运行后)。我找不到类似OnPeechRecognitionReady listener的内容。我怎样才能抓住这个事件来制作progressBar?

我用这种方法初始化识别器

private fun initSpeechRecognizer() {
        speechIntent = Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH)
        speechIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE, "en-US")
        speechIntent.putExtra(RecognizerIntent.EXTRA_CALLING_PACKAGE, packageName)
        speechRecognizer = SpeechRecognizer.createSpeechRecognizer(this)
        speechRecognizer.setRecognitionListener(object : RecognitionListenerAdapter(){
            override fun onResults(results: Bundle) {
                val matches = results.getStringArrayList(SpeechRecognizer.RESULTS_RECOGNITION)
                tv_speech.text = matches[0]
                btn_speech.isChecked = false
            }
        })
    }