code: def generate_wakeword_pieces(self, volume):
          
          while True:
              target = 1 if random() > 0.5 else 0
              it = self.pos_files_it if target else self.neg_files_it
              sample_file = next(it)
              yield self.layer_with(self.normalize_volume_to(load_audio(sample_file), volume), target)
              yield self.layer_with(np.zeros(int(pr.sample_rate * (0.5 + 2.0 * random()))), 0)
docs: Generates chunks of audio that represent the wakeword stream