Error in torchaudio.load when loading dataset

hello
I tried to learn using the LibriSpeech dataset but failed

I was able to get into DataLoader, but I got an error at for i, (___) in enumerate(train_loader):
Apparently it’s at torchaudio.load

Traceback (most recent call last):
  File "test.py", line 187, in <module>
    main()
  File "test.py", line 181, in main
    chapter_id,utterance_id,) in enumerate(train_loader):
  File "C:\Users\PC_User\Anaconda3\envs\newflan22a08m14d\lib\site-packages\torch\utils\data\dataloader.py", line 681, in __next__
    data = self._next_data()
  File "C:\Users\PC_User\Anaconda3\envs\newflan22a08m14d\lib\site-packages\torch\utils\data\dataloader.py", line 721, in _next_data
    data = self._dataset_fetcher.fetch(index)  # may raise StopIteration
  File "C:\Users\PC_User\Anaconda3\envs\newflan22a08m14d\lib\site-packages\torch\utils\data\_utils\fetch.py", line 49, in fetch
    data = [self.dataset[idx] for idx in possibly_batched_index]
  File "C:\Users\PC_User\Anaconda3\envs\newflan22a08m14d\lib\site-packages\torch\utils\data\_utils\fetch.py", line 49, in <listcomp>
    data = [self.dataset[idx] for idx in possibly_batched_index]
  File "C:\Users\PC_User\Desktop\ml-agents-0.15.0\mem_apri_tests\AI\voice_net2\detaset.py", line 133, in __getitem__
    return load_librispeech_item(fileid, self._path, self._ext_audio, self._ext_txt)
  File "C:\Users\PC_User\Desktop\ml-agents-0.15.0\mem_apri_tests\AI\voice_net2\detaset.py", line 55, in load_librispeech_item
    waveform, sample_rate = torchaudio.load(file_audio)
  File "C:\Users\PC_User\Anaconda3\envs\newflan22a08m14d\lib\site-packages\torchaudio\backend\no_backend.py", line 16, in load
    raise RuntimeError("No audio I/O backend is available.")
RuntimeError: No audio I/O backend is available.

I don’t know if it’s related, but I also get a warning like this

C:\Users\PC_User\Anaconda3\envs\newflan22a08m14d\lib\site-packages\torchvision\io\image.py:13: UserWarning: Failed to load image Python extension:
  warn(f"Failed to load image Python extension: {e}")
C:\Users\PC_User\Anaconda3\envs\newflan22a08m14d\lib\site-packages\torchaudio\backend\utils.py:62: UserWarning: No audio backend is available.
  warnings.warn("No audio backend is available.")

environment
pytorch 1.12.1 py3.7_cuda11.3_cudnn8_0 pytorch
python 3.7
os win10
anaconda

Here is the reference
https://pytorch.org/audio/stable/_modules/torchaudio/datasets/librispeech.html

Your torchaudio build doesn’t find any supported backend.
On Windows soundfile would be the default as exmplained here, but you might need to follow these instructions first:

"soundfile" backend requires SoundFile. Please refer to the SoundFile documentation for the installation.