code: def normalize_volume(
      wav, target_dBFS, increase_only=False, decrease_only=False
  ):
      if increase_only and decrease_only:
          raise ValueError(
              "Both increase only and decrease only are set"
          )
      dBFS_change = target_dBFS - 10 * np.log10(np.mean(wav**2))
      if (dBFS_change < 0 and increase_only) or (
          dBFS_change > 0 and decrease_only
      ):
          return wav
      return wav * (10 ** (dBFS_change / 20))
  
file_path: TTS/TTS/vc/modules/freevc/speaker_encoder/audio.py
imports: import struct
  from pathlib import Path
  from typing import Optional, Union
  import librosa
  import numpy
  from scipy.ndimage.morphology import binary_dilation
  from TTS.vc.modules.freevc.speaker_encoder.hparams import *
label_desc: Use image node_id 3 for calling a global function with example usage: normalize_volume(wav, target_dBFS, increase_only, decrease_only) and returns: unknown, wav