为什么我的语音识别无响应？

Question

为通过googles api进行语音识别而格式化的代码可以正常运行，但是，它只是长时间聆听并且不会停止...有人可以指导我进行更正。谢谢

import speech_recognition as sr


def main():
    r = sr.Recognizer()

    with sr.Microphone() as source:
        r.adjust_for_ambient_noise(source)

        print("Please say something...")

        audio = r.listen(source)

        try:
            print("You have said : \n" + r.recognize_google(audio))

        except Exception as e:
            print("Error : " + str(e))

if __name__== "__main__":
   main()