class_docstr: Utterance-level CMVN (cepstral mean and variance normalization)
code: def from_config_dict(cls, config=None):
      _config = {} if config is None else config
      return UtteranceCMVN(
          _config.get("norm_means", True),
          _config.get("norm_vars", True),
      )
  
imports: import numpy
  from fairseq.data.audio.feature_transforms import AudioFeatureTransform, register_audio_feature_transform
label_desc: Use image node_id 1 for calling the UtteranceCMVN obj's underlying member method code with example usage: obj.from_config_dict(cls, config) and returns: UtteranceCMVN