continuous_speech_recognition.kt

private var isActivated: Boolean = false
private val activationKeyword: String = "<YOUR_KEYWORD>"

override fun onResults(results: Bundle) {
    val matches = results.getStringArrayList(SpeechRecognizer.RESULTS_RECOGNITION)
    val scores = results.getFloatArray(SpeechRecognizer.CONFIDENCE_SCORES)
    if (matches != null) {
        if (isActivated) {
            isActivated = false
            stopRecognition()
        } else {
            matches.firstOrNull { it.contains(other = activationKeyword, ignoreCase = true) }
                    ?.let {
                        isActivated = true
                    }
            startRecognition()
        }
    }
}