def transformer_librispeech_with_area_attention():
  """HParams for training ASR model on Librispeech on TPU v2."""
  hparams = transformer_librispeech_tpu_v2()
  hparams.num_area_layers = 3  # area attn on first 3 encoder and decoder layers
  hparams.max_area_width = 5
  hparams.area_key_mode = "concat"
  hparams.area_value_mode = "sum"
  return hparams
HParams for training ASR model on Librispeech on TPU v2.
tensor2tensor/models/transformer.py