code: def test_background_noise(self):
      # noise > audio
      aug = naa.NoiseAug(noises=[self.noise])
      augmented_data = aug.augment(self.audio)
      augmented_audio = augmented_data[0]
      self.assertTrue(augmented_audio is not None)
  
      # audio > noise
      aug = naa.NoiseAug(noises=[self.audio])
      augmented_data = aug.augment(self.audio)
      augmented_audio = augmented_data[0]
      self.assertTrue(augmented_audio is not None)
  
file_path: nlpaug/test/augmenter/audio/test_noise.py
imports: import unittest
  import os
  import numpy
  from dotenv import load_dotenv
  import nlpaug.augmenter.audio
  from nlpaug.util import AudioLoader
label_desc: Use image node_id 5 for calling the TestNoise obj's underlying member method code with example usage: obj.test_background_noise() without return types