def callback_recv()

in listen_and_play.py [0:0]


    def callback_recv(outdata, frames, time, status):
        if not recv_queue.empty():
            data = recv_queue.get()
            outdata[: len(data)] = data
            outdata[len(data) :] = b"\x00" * (len(outdata) - len(data))
        else:
            outdata[:] = b"\x00" * len(outdata)