class_docstr: *Tedlium* :cite:`rousseau2012tedlium` dataset (releases 1,2 and 3).
  
  Args:
      root (str or Path): Path to the directory where the dataset is found or downloaded.
      release (str, optional): Release version.
          Allowed values are ``"release1"``, ``"release2"`` or ``"release3"``.
          (default: ``"release1"``).
      subset (str, optional): The subset of dataset to use. Valid options are ``"train"``, ``"dev"``,
          and ``"test"``. Defaults to ``"train"``.
      download (bool, optional):
          Whether to download the dataset if it is not found at root path. (default: ``False``).
      audio_ext (str, optional): extension for audio file (default: ``".sph"``)
docstr: dict[str, tuple[str]]: Phonemes. Mapping from word to tuple of phonemes.
  Note that some words have empty phonemes.
docstr_tok: ["dict","[","str",",","tuple","[","str","]","]",":","Phonemes",".","Mapping","from","word","to","tuple","of","phonemes",".","Note","that","some","words","have","empty","phonemes","."]
code: def phoneme_dict(self):
      """dict[str, tuple[str]]: Phonemes. Mapping from word to tuple of phonemes.
      Note that some words have empty phonemes.
      """
      # Read phoneme dictionary
      if not self._phoneme_dict:
          self._phoneme_dict = {}
          with open(self._dict_path, "r", encoding="utf-8") as f:
              for line in f.readlines():
                  content = line.strip().split()
                  self._phoneme_dict[content[0]] = tuple(
                      content[1:]
                  )  # content[1:] can be empty list
      return self._phoneme_dict.copy()
  
file_path: audio/src/torchaudio/datasets/tedlium.py
imports: import os
  from pathlib import Path
  from typing import Tuple, Union
  import torchaudio
  from torch import Tensor
  from torch.utils.data import Dataset
  from torchaudio._internal import download_url_to_file
  from torchaudio.datasets.utils import _extract_tar
label_desc: Use image node_id 6 for calling the TEDLIUM obj's underlying member method code with example usage: obj.phoneme_dict() and returns: self