code: def send_audio(self,
                     left_channel,
                     right_channel,
                     frame_counter=None):
          
          if frame_counter is None:
              frame_counter = self.audio_frame_counter
              self.audio_frame_counter += 1
  
          self.q_audio.put((frame_counter, left_channel, right_channel))
docs: Add the audio samples to the stream. The left and the right
          channel should have the same shape.
  
          :param left_channel: array containing the audio signal.
          :type left_channel: numpy array with shape (k, )
              containing values between -1.0 and 1.0. l can be any integer
          :param right_channel: array containing the audio signal.
          :type right_channel: numpy array with shape (k, )
              containing values between -1.0 and 1.0. l can be any integer
          :param frame_counter: frame position number within stream.
              Provide this when multi-threading to make sure frames don't
              switch position
          :type frame_counter: int