class_docstr: Featurizer that converts wavs to Mel Spectrograms.
  See AudioToMelSpectrogramPreprocessor for args.
class_docstr_tok: ["Featurizer","that","converts","wavs","to","Mel","Spectrograms",".","See","AudioToMelSpectrogramPreprocessor","for","args","."]
code: def filter_banks(self):
      return self.fb
  
imports: import math
  import random
  from typing import Optional, Tuple, Union
  import librosa
  import numpy
  import torch
  import torch.nn
  from nemo.collections.asr.parts.preprocessing.perturb import AudioAugmentor
  from nemo.collections.asr.parts.preprocessing.segment import AudioSegment
  from nemo.utils import logging
label_desc: Use image node_id 4 for calling the FilterbankFeatures obj's underlying member method code with example usage: obj.filter_banks() and returns: self