Callback function for the pyaudio stream. Don't use directly.

def get_frame(self, in_data, frame_count, time_info, status):
		""" Callback function for the pyaudio stream. Don't use directly. """
		while self.keep_listening:
			try:
				frame = self.queue.get(False, timeout=queue_timeout)
				return (frame, pyaudio.paContinue)
			except Empty:
				pass
		return (None, pyaudio.paComplete)