Vosk offline speech recognition and self learning conversation

def vosk_stt(lang, model):
    """
    獲取錄音訊息, 並傳回文字
    """
    global interrupted
    global lang
    global model
    if lang == '':
        lang = 'en'
    if model == '':
        model = 'model'

    r = sr.Recognizer() ## 進行錄音
    r.pause_threshold = 0.5 ## 語音辨識間隔
    with sr.Microphone() as source: ## 設定microphone
        try:
            audio = r.listen(source, timeout=5) ## 持續接收語音並存入audio
        except sr.WaitTimeoutError:
            print('沒有接收到語音')
            return
        except sr.UnknownValueError: