class_docstr: Base class for speech recognition problems.
code: def input_space_id(self):
      return problem.SpaceID.AUDIO_SPECTRAL
  
imports: import numpy
  from tensor2tensor.data_generators import audio_encoder
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import text_encoder
  from tensor2tensor.layers import common_audio
  from tensor2tensor.layers import common_layers
  from tensor2tensor.layers import modalities
  from tensor2tensor.utils import metrics
  import tensorflow.compat.v1
label_desc: Use image node_id 3 for calling the SpeechRecognitionProblem obj's underlying member method code with example usage: obj.input_space_id() and returns: problem