code: def manipulate(self, data, loudness_level, time_start, time_end):
      # https://arxiv.org/pdf/2001.01401.pdf
      aug_data = data.copy()
      aug_data[:, time_start:time_end] = (
          aug_data[:, time_start:time_end] * loudness_level * 1000
      )
      return aug_data
  
imports: import numpy
  from nlpaug.model.spectrogram import Spectrogram
label_desc: Use image node_id 2 for calling the Loudness obj's underlying member method code with example usage: obj.manipulate(data, loudness_level, time_start, time_end) and returns: aug_data