docstr: Check if MFCC-DCT norms work correctly.
docstr_tok: ["Check","if","MFCC-DCT","norms","work","correctly","."]
code: def test_mfcc_norms(self):
      """Check if MFCC-DCT norms work correctly."""
      sample_rate = 16000
      audio = common_utils.get_whitenoise(sample_rate=sample_rate)
  
      n_mfcc = 40
      n_mels = 128
      mfcc_transform = torchaudio.transforms.MFCC(
          sample_rate=sample_rate, n_mfcc=n_mfcc, norm="ortho"
      )
      # check norms work correctly
      mfcc_transform_norm_none = torchaudio.transforms.MFCC(
          sample_rate=sample_rate, n_mfcc=n_mfcc, norm=None
      )
      torch_mfcc_norm_none = mfcc_transform_norm_none(
          audio
      )  # (1, 40, 81)
  
      norm_check = mfcc_transform(audio)
      norm_check[:, 0, :] *= math.sqrt(n_mels) * 2
      norm_check[:, 1:, :] *= math.sqrt(n_mels / 2) * 2
  
      self.assertEqual(torch_mfcc_norm_none, norm_check)
  
imports: import math
  import torch
  import torchaudio
  import torchaudio.functional
  import torchaudio.transforms
  from torchaudio_unittest import common_utils
label_desc: Use image node_id 9 for calling the Tester obj's underlying member method code with example usage: obj.test_mfcc_norms() without return types