class_docstr: Base class of speech dataset.
class_docstr_tok: ["Base","class","of","speech","dataset","."]
code: def __init__(
      self,
      base_path: str,
      data_file: str,
      mode: Optional[str] = "train",
  ):
      self.data_file = os.path.join(base_path, data_file)
      self.mode = mode
  
imports: import csv
  import io
  import os
  from typing import Dict, List, Optional, Tuple, Union
  import numpy
  import paddle
  from paddlehub.utils.utils import extract_melspectrogram
label_desc: Use image node_id 1 to create a new BaseAudioDataset object from inherited base classes: object with example: obj = BaseAudioDataset(base_path, data_file, mode)